bluuebunny/crossref_metadata_2025 huggingface dataset:
Solving the problem of logistics center location based on the AHP method
Authors: Kauf Sabina , Tłuczak Agnieszka
Published: July 2018

The aim of this paper is to present the method of locating logistic centres in a regular hierarchical logistics network. The problem is to determine the optimal location of logistic centres with given selection criteria. Among many methods, the authors will decide on the use of the AHP method, which is an effective tool for selecting a location.
Effects of substrate temperature on the properties of the indium tin oxide thin films deposited by sputtering method
Authors: Wu Chia-Ching , Diao Chien-Chen
Published: July 2018

High-quality transparent conductive indium tin oxide (ITO) thin films were deposited on glass substrates using radio frequency sputtering method. The structure and electrical and optical properties of the ITO thin films were mainly investigated. The ITO thin films showed strong diffraction peak having a preferred orientation along the [111] direction as the deposition temperature at 120 to 160 °C. In the transmission spectra, the optical transmittance increased in the visible range as the deposition temperature increased from RT to 160 °C. A minimum resistivity of 3.06×10-3 Ω-cm was obtained for the ITO thin film deposition at 160 °C.
Numerical simulation and design of casting system for stainless steel exhaust manifold
Authors: Huang Pei-Hsing , Kuo Jenn-Kun , Fang Te-Hua , Wu Wei-ren
Published: July 2018

During operation, exhaust manifolds must bear the corrosion of high temperatures and repeated stress, which can easily lead to cavitation, corrosion, and creeping damage in the casting structure and affect product safety. To improve the structure of exhaust manifolds and increase their service life, we employed AnyCasting mold flow analysis to SUS304 stainless steel exhaust manifolds. We examined the influence of casting system design and process parameters such as ceramic shell temperature, casting temperature, and pouring speed on the filling and solidification processes of the liquid metal. Finally, we used the Niyama criterion to predict the probability and distribution of shrinkage porosity defects in the exhaust manifold and made improvements to enhance the quality of exhaust manifold castings. Keywords: exhaust manifold, mold flow analysis, casting system.
An assessment of transmission efficiency on a hard disk’s vibration
Authors: Chang Ying-Chun , Cheng Ho-Chih , Chiu Min-Chie , Chang Min-Shiang
Published: July 2018

At present, there is a trend to design a hard disk with a larger capacity, a faster revolution speed, and a precise mechanism. Therefore, the influence of data transmission with respect to vibration is obvious. To reduce interference of the vibrational impact on the data transmission efficiency, vibrational abatement on the hard disk using the damping material becomes crucial. Because of the complicated relationship for the damping coefficient and spring constant to the hardness (D1, D2, and D3) of the damping material installed under the hard disk, it is difficult to theoretically assess an optimal hardness combination of the damping material. Therefore, an alternative way by using an experimental study in conjunction with Taguchi method, an Artificial Neural Network (ANN), and a GA Method is proposed. In this paper, a hard disk is placed on a vibration tester that is an analogue to a dynamic vibrational circumstance induced by a vibrational base. The data transfer rate of the hard disk will be detected by using IOmeter software under various base-excitation accelerations, tilted angles of the hard disk, and targeted frequencies. To reduce the vibrational impact on the data transmission efficiency, an assessment of an optimal three-layer damping material installed under the hard disk using the Taguchi method, the Artificial Neural Network (ANN), and the GA Method is proposed. Before the optimization of the damping material is performed, the required experimental sets (the hardness for three layers of damping material) of the data transmission testing with respect to various design parameters will be determined by using the Taguchi method. The ANN, a simplified objective function (OBJ), will be established by inputting the hardness of three layers of damping material and their related data transmission efficiency at three targeted frequencies. Thereafter, the optimal hardness for three layers of the damping material will be obtained using a genetic algorithm (GA). Consequently, the optimal hardness of the three-layer damping material with respect to various tilted angles and target frequencies will be assessed.
Based on FP LDs with split band technique in two-channel fiber optical CATV transport system
Authors: Tsai Wen-Shing , Dai Hong-Yu , Li Chung-Yi
Published: July 2018

This study proposes a two-channel fiber optic cable television (CATV) transport system based on Fabry–Perot laser diodes (FP-LDs) with a split band technique. To reduce the interference between channels, we apply the split band technique to two channels with different frequencies by using two converters at each moment. In this two-channel transmission scheme, composite second-order (CSO) and composite triple-beat (CTB) distortions induced by the systems are possibly confined in unused channels and result in good transmission performances. Through a 40 km standard single-mode fiber transmission, excellent performances of carrier-to-noise ratio (≥50 dB), CSO (≥70 dB), and CTB (≥72 dB) are obtained using the proposed fiber optic CATV transport systems. The proposed systems employing FP-LDs with a split band technique are also simpler and more cost effective than conventional externally modulated systems.
The effect of thrust force in drilling composite materials using step core-ball drill
Authors: Teng Hsing-Ming , Tsao Chung-Chen
Published: July 2018

Composite materials have gained increasing popularity over the past few decades due to their superior mechanical properties, such as high strength-to-weight ratio, fighting against high temperature and corrosion resistance. The assembly of enormous aeronautical components and structures require the machining of composite materials. Drilling is the most important hole-making process in the final assembly. When drilling composite materials, a number of defects are generating. Delamination caused by drilling thrust has been showed as one of the most problematic defects after drilling composite laminates. With a pressing need for decreased delamination, many studies are turning more and more toward tool geometry and machining parameters. Drilling of composite plates using a step core-ball drill, which is a special drill to improve the chip flow and reduces the thrust force at the exit of hole, is investigated in this study. The experimental results found that the step core-ball drill was efficient in drilling of carbon fiber reinforced plastic (CFRP) and did not produce loading on the drill exit at the proper drilling conditions. The results obtained from this study feeding back for fundamental research efforts could steer future studies on the drilling composite materials in the most promising direction.
Multi-tasking multi-machine scheduling system for multi-stage multi-criteria production
Authors: Liu Shao-Chen , Chen Yu-Ren , Kuo Cheng-Ju , Lin Tzu-Yu , Ting Kuo-Cheng , Yang Don-Lin , Chen Hsi-Min , Chen Yi-Chung
Published: July 2018

In recent years, many major manufacturers have been incorporating Industry 4.0 technologies such as preventive fault detection, automated scheduling algorithms, and component management to increase productivity and reduce production costs. Achieving this objective requires a substantial amount of working capital to acquire large quantities of new machinery, equipment to extract data from the machinery, and high-priced big data analysis software. However, most factories in the world are small-or medium-sized companies and have not enough capital to replace their machinery or purchase big data analysis software. It is therefore almost impossible for these factories to reach the goal of Industry 4.0. Furthermore, most of the conventional automated production scheduling methods only consider a single criterion in scheduling, which is not applicable for actual situations. This study therefore proposed a multi-tasking multi-machine scheduling system for multi-stage multi-criteria production to address various shortcomings in existing methods. To achieve this goal, we proposed a novel concept based on skyline queries to assist in the scheduling process. Also, a data structure of "heap" is applied in this work to accelerate the scheduling process. The experimental results demonstrated the validity of the proposed approach.
Computer aided design and analysis on distributors in DAC columns
Authors: Lin Chen-Jiann , Tse Tseng-Hsiang , Che Liu-Cheng , Tsai Liang-Ming
Published: July 2018

Dynamic axial compression (DAC) columns are key elements in simulated moving bed, which is a chromatography process in drug industry and chemical engineering. In this study, rules for designing distributors are proposed based on mass conservation and validated by experiments, the computer aided design (CAD) and the computational fluid dynamics (CFD). Experimental works are conducted to choose feasible numerical parameters for simulations. In CFD, the transient laminar flow fields are governed by the momentum and species transport equations with Darcy's law to model the porous zone in the packed bed. Results show that CFD combined with CAD solid modelling is a good approach to explore detailed flow fields in DAC columns and carry out parameter analysis for innovative designs. For further testing and evaluation, a new model of compound distributor is designed, 3D printed and processed in factory for practical applications in preparative chromatography.
Forming parameters optimizations with drawing force and die stress in wire rod drawing using rotating die under Coulomb friction
Authors: Tiong Ing-Kiat , Chai Un-Chin , Tzou Gow-Yi
Published: July 2018

An optimization research is performed on the related forming parameters of wire rod drawing through a rotating die under Coulomb friction. The optimization research is conducted through finite element method (FEM) simulation combined with Taguchi method. There are two drawing characteristic optimizations have been carried out. They are the optimizations with drawing force and die stress. The forming parameters considered in this study are half die angle, frictional coefficient, die fillet, and rotating angular velocity of the rotating die. The same procedure is carried out in both optimizations. The geometrical models of the wire rod, top die and rotating die are constructed firstly in SolidWorks and imported into the FEM simulation software named DEFORM 3D. With the aid of Taguchi method, the simulation experiments are carried out. The results such as drawing force, die stress, and the corresponding signal-to-noise (S/N) ratio are obtained and compared. The influence rank of the forming parameters and the optimal combination of parameters are obtained through the response table for both optimizations. The results such as effective stress, effective strain, velocity field, drawing force, and die stress are studied. The results show that the minimizations of drawing force and die stress are successfully achieved.
Design of deep learning on intelligent levelling system for industry 4.0 technology
Authors: Tsai Sung-Yu , Chang Jen-Yuan (James)
Published: July 2018

Sheet metal is widely used in the industry for metal forming purposes, such as metal stamping and laser cutting as shown. It is often winded and stored in a coil form in order for better transportation. In the recent years, industry 4.0 has been a widely discussed topic in terms of industry manufacturing solutions, the manufacturing is required to be more flexible, efficient and also require more customization. In conventional coil levelling system, the machine settings are often tuned by the experienced technicians with many years of experiences. However, as industry 4.0 focused on information process through real objects, it is required to digitize the experience through deep learning method. Therefore, it is required to be adapted through data information transfer between real world and machines, or even machines to machines. In addition, the data information is often processed and analysed through computers which are often desired to mimic the operations of the experienced machine technicians through machine learning or deep learning methods. This paper is aimed to describe and develop the deep learning algorithm with application based on coil levelling system. Finally, through this paper, design of the deep learning algorithm with application based on coil levelling system is verified.
Embedded smart box for legacy machines to approach to I 4.0 in smart manufacturing
Authors: Fan Yi-Chih , Chang Jen-Yuan (James)
Published: July 2018

This paper introduces the design of a Linux-based embedded controller which includes machine state detection application for legacy machines and manufacturing line. For Industrie 4.0 (I4.0), it is important to acquire, manipulate, and transmit machine operating states or physical data to form useful information. However, many existing legacy machines lack of controller or sensor(s) to response to their operating status. Some machine controllers cannot be connected to provide internal parameter(s) by means of communication. Gathering machine operating state should be the first priority to approach to I4.0. This paper adopts widely used Raspberry PI as the core platform to build Embedded Smart Box (ESB). It uses external sensors to detect the machine operating status to compute the machine's availability (one of Overall Equipment Efficiency factors) and measures current to calculate the power consumption. In this research, the combination of embedded system and sensors can be a smart box for legacy machines. Such cost-effective design would help users to take the useful data from the machines and construct the base of I4.0 system even without the existence of the controller. This embedded-based design methodology has great potential implications that might fundamentally change the legacy factories into I4.0 smart one.
Application of hot forming quenching on patchwork blank using two-stage refilled friction stir spot welding
Authors: Jo D.S. , Kim J.H. , Ko D.C. , Kim B.M.
Published: July 2018

The purpose of this study is to apply Hot Forming Quenching (HFQ) on Patchwork Blank of AA6061 using Two-stage refilled Friction Stir Spot Welding (TFSSW). TFSSW is a developed joining method to improve joint strength of conventional Friction Stir Spot Welding (FSSW) and it consists of two stages. The first stage is a conventional FSSW process and second stage is a refilling process for refilling keyhole. The Design of Experiment (DOE) was used to optimize the TFSSW process parameters. A hat shape forming test was performed using a patchwork blank manufactured with the optimal process parameters to investigate validity of applying HFQ. Formed hat shape part was sequentially heat treated with artificial aging (T6) condition. The hardness of the weld zone was measured to confirm a drop of mechanical property in comparison with the conventional cold forming, which shows the validity of HFQ application to patchwork blank using TFSSW.
Study on design of temperature - dependence of sublimation transfer roller
Authors: Hsieh Ming-Chu , Lin Jung-Sen
Published: July 2018

Sublimation trasnfer machine's hot roller, a compression type electronic heater, is made of ceramic core which is wrapped with nickel-chromium alloy heater. This roller is insulated with magnesium oxide. When the power is on, the heat is generated. Heat transfers are from high temperature area to low temperature area, and it causes the non-uniform temperature surface and the roller surface distorsion. Such effects always increase with larger diameter of the roller and longer the roller. In order to predict the sublimation transfer machine's roller temperature distribution and validate it, we construct the roller's 3D temperature model and use ANSYS steady state heat transfer analysis module to calculate the power dissipation and simulate it. Final data shall help us to design sublimation transfer machines' roller.
BEFORE-Studie
Authors: Sokolowski Tobias , Voet Bernard
Published: July 2018

Studie Die klinische, randomisierte, doppelt-blinde BEFORE-Studie wurde zum Nachweis der Wirksamkeit und Verträglichkeit einer Wirkstoffkombination bestehend aus einem speziellen Polyglucosamin und einem Glucomannan durchgeführt. 165 übergewichtige Teilnehmer (BMI > 27) wurden in die Studie aufgenommen und randomisiert auf drei Behandlungsgruppen aufgeteilt. Die Wirkstoffe in der Prüfmedikation sind aus natürlichen Ausgangsmaterialien hergestellt (Aspergillus niger und Amorphophallus konjac) und enthalten keine Stoffe tierischen Ursprungs. Die Probanden erhielten in den drei Behandlungsarmen entweder ein Placebo oder die einfache Dosis Polyglucosamin + Glucomannan (tägl. Dosis von 1,5 g und 3,0 g) oder die doppelte Dosis Polyglucosamin mit einer um 34 % erhöhten Dosis an Glucomannan (tägl. Dosis von 3 g und 4,02 g) dreimal täglich vor einer Mahlzeit über einen Zeitraum von 8 Wochen.

Ergebnisse Die Studie konnte eine relevante Gewichtsreduktion in beiden Verum-Gruppen über den Untersuchungszeitraum von 56 Tagen nachweisen, mit einer signifikanten Gewichtsreduktion von –0,89 ± 2,1 kg (p = 0,0044) und –1,01 ± 2,1 kg (p = 0,0006) in den beiden Verum-Gruppen und einer nicht signifikanten Veränderung von –0,09 ± 1,4 kg (p > 0,75) in der Placebo-Gruppe.

Schlussfolgerung Obwohl die Studienteilnehmer ihren Lebensstil und ihre Ernährungsgewohnheiten nicht änderten, konnte durch die Einnahme des Prüfproduktes ein relevanter Gewichtsverlust in beiden Verum-Gruppen erzielt werden, während in der Placebo-Gruppe keine relevante Gewichtsveränderung beobachtet wurde. Insgesamt konnte die Studie eine statistisch signifikante Wirkung auf die Reduktion des Körpergewichts im Vergleich zum Ausgangswert und eine gute Verträglichkeit durch beide Verum-Produkte ohne eine zusätzliche Diät (Kalorienreduktion) oder erhöhte körperliche Aktivität nachweisen.
Behandlung im Voraus Planen (BVP): Eine Übersichtsarbeit über das Vorsorgeverhalten von Frauen und Männern in Deutschland
Authors: Gadebusch Bondio Mariacarla , Wagner Anna Julia Maria , Krieger Rico , Weiß Leonard , Kinnebrock Susanne
Published: July 2018

Hintergrund Der Wunsch, bis zum Lebensende über sich zu verfügen, hat in unserer Gesellschaft einen hohen Stellenwert erreicht. Frauen und Männer unterschiedlichen Alters, sozio- und bildungsbiografischen Hintergrunds und verschiedener kultureller Prägungen entscheiden zunehmend über künftige Behandlungen im Voraus (Behandlung im Voraus planen, BVP).

Ziel der Arbeit Identifikation und Analyse von Forschungsliteratur über das Vorsorgeverhalten von Männern und Frauen in Deutschland. Im Fokus stehen geschlechterspezifische Unterschiede.

Material und Methoden Systematischer Review von empirischen Studien mit geschlechterspezifischen Daten zum Vorsorgeverhalten in Deutschland. Dezidierte Analyse von 21 der 479 extrahierten Artikel.

Ergebnisse Bei antizipativen Behandlungsentscheidungen zeigt sich, dass das Vorsorgeverhalten von interagierenden Faktoren wie Geschlecht, Alter, kultureller und ethnischer Hintergrund, Religion und Bildung geprägt wird. Eine rein geschlechtsspezifisch erklärbare Prävalenz von Vorsorgeverhalten lässt sich aus den Studien nicht ableiten. Dieses prima facie negative Ergebnis ist z.T. auf das Design der Studien selbst zurückzuführen. Heterogene Daten und wenig ausgeprägte Geschlechtersensibilität lassen die Frage nach dem Verhältnis von Vorsorgeverhalten, Geschlecht und Gender i.d.R. unbeantwortet.

Diskussion Die analysierten Studien reduzieren die Dimension Geschlecht auf eine dualistische Klassifikation, blenden individuelle Rollenbilder und Haltungen (Gender) aus und lassen ebenso geographisch-kulturelle Kontexte unberücksichtigt. Hieraus ergibt sich ein Forschungsdesiderat für Studien mit einem reflektierten gender- und kultursensiblen Fokus.
Identification of Species in the Aromatic Spice Family Apiaceae Using DNA Mini-barcodes
Authors: Parveen Iffat , Techen Natascha , Khan Ikhlas
Published: July 2018

The species of the aromatic plant family Apiaceae are mainly used as spices and foods, but the family also includes medicinal and some poisonous plant species. Due to the similar chemical compounds or aroma and morphology, the poisonous species are often mistaken for the edible aromatic species. It is therefore imperative to correctly identify the species present at the initial raw stage samples to ensure product safety and efficacy. At the molecular level, plant species can be identified using DNA loci either from nuclear or plastid genome with easily available universal oligonucleotides, a technique called DNA barcoding. However, this is possible when single-species plant material is present but may not work on a mixture of plants species. Another disadvantage is that using universal oligonucleotides is of limited help, especially if the adulterating material is present in low quantities. On the other hand, if using the species-specific oligonucleotides, only single specific adulterating plant material could be detected and, consequently, the unexpected adulterants may go undetected. Therefore, in the current work, four degenerated oligonucleotides from ITS1 and ITS2 regions of the nuclear genome were designed that can bind to a variety of Apiaceae genera only and not to other genera belonging to different plant families. These family-specific oligonucleotides were able to amplify a diagnostic PCR product from 16 Apiaceae species that, upon sequencing, revealed the identity of the plant it was derived from. The size of these products is around 140 bp for ITS1 and approximately 80 bp for the ITS2 region. The size range of the amplified products falls in the category of a desired mini-barcode size to be used for damaged/fragmented DNA and next generation sequencing.
Fluorofluorescent Perylene Bisimides
Authors: Swager Timothy , Yoshinaga Kosuke
Published: July 2018

Perfluorinated liquids can exhibit immiscibility with organic solvents and water, and provide orthogonal opportunities in chemistry. Examples of emissive dyes that display only fluorous phase solubility are limited, despite the many potential applications. Perylene bisimides are among the most versatile dyes and are known for their outstanding stability and high quantum yields. Herein, we report the synthesis of two new “fluorofluorescent” perylene bisimide dyes, designed to be soluble in the fluorous phases. These two dyes possess unique photophysical properties, including dramatic increases in fluorescence quantum yields when treated with Brønsted acids as well as aggregation in the fluorous phase.
Premature Infants Conceived with Assisted Reproductive Technology: An Analysis of Infant Morbidity, Compared with Infants Conceived Naturally
Authors: Berg Jennifer , Keszler Martin , Abubakar Kabir , Scala Melissa
Published: July 2018

Objective This article evaluates the morbidity of infants born via assisted reproductive technology (ART) compared with matched naturally conceived infants.

Study Design This is a retrospective review of maternal and infant data among inborn infants conceived via ART and matched control infants born at 30 to 34 weeks' gestational age (GA) between 2006 and 2012. Data were analyzed using paired t-test or Wilcoxo–Mann–Whitney test for continuous and Fisher's exact test for categorical variables. p-Value of < 0.05 was considered significant.

Result Of 120 study infants, 60 were conceived via ART and 60 naturally. Control infants were matched for GA, gender, race, and multiple gestations. ART infants required more respiratory support and took longer to reach full feeds compared with control infants.

Conclusion Infants born via ART are physiologically more immature with more intensive care needs than naturally conceived infants of similar gestation, potentially increasing health care costs. This immaturity should be considered when planning early delivery in these pregnancies.
Die Mentalismusfrage
Authors: Pawelzik M. R.
Published: July 2018

Die Mentalismusfrage zielt auf ein zentrales theoretisches Problem der Psychiatrie: Wie ist das Psychische richtig zu verstehen? Dass diese Frage bis heute nicht schlüssig beantwortet werden kann, liegt nicht allein an unserer empirischen Ignoranz. Die Schwierigkeiten, eine Antwort zu finden, sind ebenso auf die bisherige Art der wissenschaftlichen Herangehensweise, d. h. auf Forschungsmethodik und Modellierung, zurückzuführen. Um etwas Licht in die infrage stehenden Zusammenhänge zu werfen, werde ich fünf Fragen stellen und tentativ zu beantworten versuchen – Fragen nach dem ontologischen Status der mentalen Sphäre, nach der Beschreibung und der Erkenntnis des Mentalen und nach seiner Stellung in der Naturgeschichte und seiner erfolgversprechendsten wissenschaftlichen Modellierung. Ziel meiner Diskussion der Fragen wird es sein, den Stellenwert der Mentalismusfrage zu verdeutlichen, das Verständnis für die zugrundeliegenden Probleme zu vertiefen und um für eine theoretische Re-Orientierung des Faches zu werben.
„Mindedness in action”
Authors: Pawelzik Markus , Fonagy Peter
Published: July 2018

Prof. Peter Fonagy, London, ein Mitbegründer der mentalisierungsbasierten Psychotherapie (MBP), im Interview mit Dr. Markus Pawelzik.
CIRSE and World Interventional Radiology
Authors: Morgan Robert , Slijepcevic Birgit
Published: July 2018

On the occasion of the 20th Indian Society of Vascular and Interventional Radiology (ISVIR) Annual Conference in Lucknow, India, in February 2018, the President of the Cardiovascular and Interventional Radiological Society of Europe (CIRSE) presented the ISVIR International Oration on the topic “CIRSE and World Interventional Radiology.” The oration addressed the current strengths but also the challenges interventional radiology (IR) is facing worldwide and emphasized the portfolio of CIRSE's activities aiming to further this innovative discipline. Four pillars for the future of IR are addressed in detail: education, certification, research and guidelines as well as communication and global collaboration. Building on these aspects, a prosperous future for IR can be expected.
Regional politics of an urban age: Can Europe’s former industrial cities create a new industrial economy to combat climate change and social unravelling?
Authors: Power Anne
Published: July 2018

Across Europe, cities are struggling to cope with the loss of industrial jobs; decay of urban infrastructure; in-migration (most often from poorer regions); outward sprawl pressures; traffic congestion and transport bottlenecks. The environmental consequences of continuing urban development are deeply threatening to the survival of both city and countryside. Growing anti-immigrant sentiments, sluggish growth and intense inequality provoke a level of disaffection and marginalisation that threaten social cohesion, with highly divisive consequences. This article, based on a ten year study of seven European cities, argues that recovery is under way in ex-industrial cities with major reinvestment from national and European funds. Transformative deals and innovations have created new jobs and led to population regrowth after years of decline. There are hopeful signs that in different parts of Europe–North, South, East and West–a new phase of growth in core cities is emerging, based on university-civic business partnerships; reuse and remodelling of existing, devalued infrastructure; reinvestment and expansion of rail and water networks; the growth in advanced manufacturing; reduced energy use and the spread of renewable energy; innovative research and technology; city centre and neighbourhood restoration and integration. Europe’s former industrial cities are part of much bigger metropolitan areas or city regions and some benefits are spreading out from core cities to more peripheral areas, although this is often swamped by poverty and unemployment, skills mismatch and inadequate reinvestment. A complex patchwork of changes is driven by a new kind of city leadership; growing collaboration between the core and periphery of cities; central government and Europe-wide concern both to devolve more powers and reduce dependence on central funds; regional devolution and metropolitan level programmes–particularly in areas of skills, research and development, infrastructure, and umbrella services backed with cash and political enthusiasm. Cities are recovering across the world’s most urban continent by combining reuse and new inventions, which deliver more sustainable economies.
High strength fiber reinforced composites with surface fibrilized aramid fibers
Authors: Nasser Jalal , Lin Jiajun , Sodano Henry
Published: July 2018

Debonding of the fiber-matrix interface is a common issue in composites, especially for aramid fiber reinforced composites due to their smooth and inert surface. Here, a novel surface treatment is developed for aramid fibers in order to enhance the interfacial properties in composites while preserving the fiber's tensile strength. The fibrilization approach follows the recent work on the aramid nanofibers and uses a solution of potassium hydroxide and dimethyl sulfoxide at room temperature. This process is performed to exfoliate the surface fibrils such that a pseudo-wiskerized fiber is prepared, which provides mechanical interlocking with the matrix. The surface bound fibrils also contain increased polar functional groups, which additionally provides improved wetting due to the enhanced compatibility of the fiber with the matrix as well as offering reactive sites to allow covalent bonding with the reactive thermosets such as epoxy. It is shown that the surface fibrilized fibers possess an 128% improved interfacial shear strength with an epoxy matrix, as well as a 62% increased short beam strength, compared with untreated fiber reinforced composites. The tensile strength of the treated fibers is demonstrated to be preserved, ensuring a significant improvement in the common failure modes without a degradation of in-plane properties. The results indicate the potential of this treatment as a simple, fast, and cost-effective method to improve not only the interface in the aramid fiber reinforced polymer matrix composites but also the bulk laminated composite.
Transition path theory from biased simulations
Authors: Bartolucci G. , Orioli S. , Faccioli P.
Published: July 2018

Transition Path Theory (TPT) provides a rigorous framework to investigate the dynamics of rare thermally activated transitions. In this theory, a central role is played by the forward committor function q+(x), which provides the ideal reaction coordinate. Furthermore, the reactive dynamics and kinetics are fully characterized in terms of two time-independent scalar and vector distributions. In this work, we develop a scheme which enables all these ingredients of TPT to be efficiently computed using the short non-equilibrium trajectories generated by means of a specific combination of enhanced path sampling techniques. In particular, first we further extend the recently introduced self-consistent path sampling algorithm in order to compute the committor q+(x). Next, we show how this result can be exploited in order to define efficient algorithms which enable us to directly sample the transition path ensemble.
Generation of keV hot near-solid density plasma states at high contrast laser-matter interaction
Authors: Rosmej O. N. , Samsonova Z. , Höfer S. , Kartashov D. , Arda C. , Khaghani D. , Schoenlein A. , Zähter S. , Hoffmann A. , Loetzsch R. , Saevert A. , Uschmann I. , Povarnitsyn M. E. , Andreev N. E. , Pugachev L. P. , Kaluza M. C. , Spielmann C.
Published: July 2018

We present experimental evidence of ultra-high energy density plasma states with the keV bulk electron temperatures and near-solid electron densities generated during the interaction of high contrast, relativistically intense laser pulses with planar metallic foils. Experiments were carried out with the Ti:Sapphire laser system where a picosecond pre-pulse was strongly reduced by the conversion of the fundamental laser frequency into 2ω. A complex diagnostics setup was used for evaluation of the electron energy distribution in a wide energy range. The bulk electron temperature and density have been measured using x-ray spectroscopy tools; the temperature of supra-thermal electrons traversing the target was determined from measured bremsstrahlung spectra; run-away electrons were detected using magnet spectrometers. Analysis of the bremsstrahlung spectra and results on measurements of the run-away electrons showed a suppression of the hot electron production in the case of the high laser contrast. Characteristic x-ray radiation has been used for evaluation of the bulk electron temperature and density. The measured Ti line radiation was simulated both in steady-state and transient approaches using the code FLYCHK that accounts for the atomic multi-level population kinetics. The best agreement between the measured and the synthetic spectrum of Ti was achieved at 1.8 keV electron temperature and 2 × 1023 cm−3 electron density. By application of Ti-foils covered with nm-thin Fe-layers, we have demonstrated that the thickness of the created keV hot dense plasma does not exceed 150 nm. Results of the pilot hydro-dynamic simulations that are based on a wide-range two-temperature Equation of States, wide-range description of all transport and optical properties, ionization, electron, and radiative heating, plasma expansion, and Maxwell equations (with a wide-range permittivity) for description of the laser absorption are in excellent agreement with experimental results. According to these simulations, the generation of keV-hot bulk electrons is caused by the collisional mechanism of the laser pulse absorption in plasmas with a near solid step-like electron density profile. The laser energy, first deposited into the nm-thin skin-layer, is then transported into 150 nm depth by the electron heat conductivity. This scenario is opposite to the volumetric character of the energy deposition produced by supra-thermal electrons.
Non-adiabatic corrections to electric current in molecular junctions due to nuclear motion at the molecule-electrode interfaces
Authors: Kershaw Vincent F. , Kosov Daniel S.
Published: July 2018

We present quantum electron transport theory that incorporates dynamical effects of motion of atoms on electrode-molecule interfaces in the calculations of the electric current. The theory is based on non-equilibrium Green’s functions. We separate time scales in the Green’s functions as fast relative time and slow central time. The derivative with respect to the central time serves as a small parameter in the theory. We solve the real-time Kadanoff-Baym equations for molecular Green’s functions using Wigner representation and keep terms up to the second order with respect to the central time derivatives. Molecular Green’s functions and consequently the electric current are expressed as functions of molecular junction coordinates as well as velocities and accelerations of molecule-electrode interface nuclei. We apply the theory to model a molecular system and study the effects of non-adiabatic nuclear motion on molecular junction conductivity.
Nature of intrinsic uncertainties in equilibrium molecular dynamics estimation of shear viscosity for simple and complex fluids
Authors: Kim Kang-Sahn , Han Myung Hoon , Kim Changho , Li Zhen , Karniadakis George Em , Lee Eok Kyun
Published: July 2018

We study two types of intrinsic uncertainties, statistical errors and system size effects, in estimating shear viscosity via equilibrium molecular dynamics simulations, and compare them with the corresponding uncertainties in evaluating the self-diffusion coefficient. Uncertainty quantification formulas for the statistical errors in the shear-stress autocorrelation function and shear viscosity are obtained under the assumption that shear stress follows a Gaussian process. Analyses of simulation results for simple and complex fluids reveal that the Gaussianity is more pronounced in the shear-stress process (related to shear viscosity estimation) compared with the velocity process of an individual molecule (related to self-diffusion coefficient). At relatively high densities corresponding to a liquid state, we observe that the shear viscosity exhibits complex size-dependent behavior unless the system is larger than a certain length scale, and beyond which, reliable shear viscosity values are obtained without any noticeable scaling behavior with respect to the system size. We verify that this size-dependent behavior is configurational and relate the characteristic length scale to the shear-stress correlation length.
Photonic Hall effect
Authors: Jahani D. , Alidoust Ghatar A. , Abaspour L. , Jahani T.
Published: July 2018

In this work, we report on the emergence of a photonic Hall effect (PHE) system within a narrow filtered background of a one-dimensional defective optical dielectric structure with graphene under the influence of a constant magnetic field regime. It is observed that at low temperature and relatively strong applied magnetic fields, electromagnetic defective transmission spectra corresponding to the two decoupled right- and left-handed polarized modes possess a step-like transmission feature which is referred to as “quantum Hall defect modes” (QHD modes or QHDs) in this paper. Tunable growing transitional transmission steps for QHDs with increasing magnetic field intensity were shown to be possible. Observation of sensitive magneto-transmission oscillations to the thermal excitations in the last plateaus slowly ascending toward unity is another special feature noted in this work. The results of this study, which is carried out based on rapid standard calculations for the transfer matrix approach is supplied with commercial simulations marking the first PHE system, promise an proper candidate for new photonic applications, especially new tunable magneto-based lenses and photonic magneto-thermal sensors.
Picosecond all-optical switching and dark pulse generation in a fibre-optic network using a plasmonic metamaterial absorber
Authors: Xomalis Angelos , Demirtzioglou Iosif , Jung Yongmin , Plum Eric , Lacava Cosimo , Petropoulos Periklis , Richardson David J. , Zheludev Nikolay I.
Published: July 2018

Coherent interaction of two light waves on a film of subwavelength thickness provides remarkable opportunities for controlling intensity and polarization of light beams as well as all-optical image processing. Here, we show that such interactions can be used for optical dark pulse generation and basic all-optical signal processing in fully fiberized coherent information networks with 1 THz bandwidth. With an encapsulated plasmonic metamaterial absorber operating in the telecommunications C-band, we demonstrate switching and dark pulse generation with 1 ps laser pulses.
CdZnTe detectors for gamma spectroscopy and x-ray photon counting at 250 × 106 photons/(mm2 s)
Authors: Prokesch Michael , Soldner Stephen A. , Sundaram Arunmozhi G.
Published: July 2018

Using the traveling heater method, we have developed commercial CdZnTe (CZT) crystal growth, fabrication, and in-house test technologies for both, photon-starved gamma spectroscopic sensors and high-flux x-ray photon-counting for medical imaging and other applications. We compare the performance of different CZT material types for gamma spectroscopy and for high-flux x-ray imaging. We demonstrate single-threshold photon counting and basic imaging capability of pixelated CZT detectors at the highest x-ray fluxes we could generate in-house, i.e., ∼250 × 106 photons/(mm2 s). We show that the test system can be used for universal, absolute flux calibration of x-ray beams based on an accurate pile-up fitting algorithm. The detectors also perform spectroscopically under high-flux, when tested with energy discriminating electronics. A brief investigation on the effects of leakage, photo, and excess currents including their temporal behavior is also presented. Sub 1% uncorrected single-pixel resolution of the 662 keV 137Cs full energy peak was achieved with the gamma spectroscopy optimized material, fabricated into pixelated sensors.
Compact, high power and high efficiency relativistic magnetron with L-band all cavity axial extraction
Authors: Xu Sha , Lei Lurong , Qin Fen , Wang Dong
Published: July 2018

To reduce the size and the weight of the relativistic magnetron (RM), a highly compact RM using an all cavity extraction and transparent cathode is investigated. Compared with the traditional RM design [Sayapin et al., IEEE Trans. Plasma Sci. 45(2), 6792062 (2017) and Sayapin and Shlapakovski, J. Appl. Phys. 109(6), 063301 (2011)] this configuration occupies only 0.55λ (radius) * 1.55λ (length). Both simulation and experimental results demonstrate that a microwave power of 508 MW is generated at 1.57 GHz when the input beam voltage is 369 kV and the corresponding efficiency is ∼33%. This provided work paths a way to finally achieve high power, high efficiency, and compact microwave sources.
Invited Article: Tuning and stabilization of optomechanical crystal cavities through NEMS integration
Authors: Grutter Karen E. , Davanço Marcelo I. , Balram Krishna C. , Srinivasan Kartik
Published: July 2018

Nanobeam optomechanical crystals, in which localized GHz frequency mechanical modes are coupled to wavelength-scale optical modes, are being employed in a variety of experiments across different material platforms. Here, we demonstrate the electrostatic tuning and stabilization of such devices, by integrating a Si3N4 slot-mode optomechanical crystal cavity with a nanoelectromechanical systems element, which controls the displacement of an additional “tuning” beam within the optical near-field of the optomechanical cavity. Under DC operation, tuning of the optical cavity wavelength across several optical linewidths with little degradation of the optical quality factor (Q ≈ 105) is observed. The AC response of the tuning mechanism is measured, revealing actuator resonance frequencies in the 10 MHz–20 MHz range, consistent with the predictions from simulations. Feedback control of the optical mode resonance frequency is demonstrated, and alternative actuator geometries are presented.
Strong correlation between B-Al-N doping concentration fluctuation and photoluminescence effects of f-SiC
Authors: Zhuo Shi-Yi , Liu Xue-Chao , Xu Ting-Xiang , Yan Cheng-Feng , Shi Er-Wei
Published: July 2018

This paper report the relationship between B-Al-N doping concentration fluctuation and photoluminescence effects of fluorescent 4H-SiC single crystals. The photoluminescence emission properties, dopant concentration, and internal quantum efficiency of B, Al and N co-doped 4H-SiC are characterized. It is found that the emission spectra exhibit a wide band that covers from about 450 nm to 750 nm. The peak intensity of the emission spectra is strongly affected by B, Al and N concentrations. By further analyses the roles of B-Al-N dopants, a hypothetical formula is proposed, which can help to profile the strong correlation between photoluminescence effects and B-Al-N doping concentrations.
Modulational instability and dynamics of multi-rogue wave solutions for the discrete Ablowitz-Ladik equation
Authors: Wen Xiao-Yong , Yan Zhenya
Published: July 2018

The higher order discrete rogue waves (RWs) of the integrable discrete Ablowitz-Ladik equation are reported using a novel discrete version of generalized perturbation Darboux transformation. The dynamical behaviors of strong and weak interactions of these RWs are analytically and numerically discussed, which exhibit the abundant wave structures. We numerically show that a small noise has the weaker effect on strong-interaction RWs than weak-interaction RWs, whose main reason may be related to main energy distributions of RWs. The interaction of two first-order RWs is shown to be non-elastic. Moreover, we find that the maximal number (Smax) of the possibly split first-order ones of higher order RWs is related to the number (Pmax) of peak points of their strongest-interaction cases, that is, Smax = (Pmax + 1)/2. The results will excite to further understand the discrete RW phenomena in nonlinear optics and relevant fields.
Fertilisation of polar nuclei and formation of early endosperms in Dendrobium catenatum: evidence for the second fertilisation in Orchidaceae
Authors: Chen Yong , Zhang Chu , Wang Xiao-feng , Ao Cheng-qi
Published: July 2018

Whether the second fertilisation, i.e. fertilisation of polar nuclei, or fusion of the second sperm with polar nuclei occurs in Orchidaceae has long been controversial because of lack of evidence. In the present study, we observed fusion and fertilisation of polar nuclei and formation of early endosperms in the orchid Dendrobium catenatum Lindl., by using a resin-embedded section technique. As the product of the second fertilisation, the primary endosperm nucleus (fertilised polar nuclei) can last until the global embryo stage, indicating that initiation of endosperm development and that of embryo development were fully asynchronous. The present study demonstrated the occurrence of the second fertilisation in D. catenatum by providing lines of new evidence.
An Efficient Synthesis of Pyrrolidinone Derivatives in the Presence of 1,1′-Butylenebis(3-sulfo-3H-imidazol-1-ium) Chloride
Authors: Khaligh Nader Ghaffari , Chong Kim Foong , Mihankhah Taraneh , Titinchi Salam , Johan Mohd Rafie , Ching Juan Joon
Published: July 2018

The catalytic efficiency of 1,1′-butylenebis(3-sulfo-3H-imidazol-1-ium) chloride as a sulfonic acid-functionalized ionic liquid was demonstrated for the synthesis of pyrrolidinone derivatives under mild conditions. The electronic effect of substituents on aniline derivatives was investigated. Further, a study on the structure–activity relationship of ionic liquids containing sulfonic groups for the synthesis of ethyl-2-(4-chlorophenyl)-4-hydroxy-5-oxo-1-(p-tolyl)-2,5-dihydro-1H-pyrrole-3-carboxylate was performed under optimal conditions. The results showed that the catalytic properties of ionic liquids containing two sulfonic or imidazole moieties with carbon spacers was superior to ionic liquids having one sulfonic or imidazole moiety with no carbon spacer.
Directly light-regulated binding of RGS-LOV photoreceptors to anionic membrane phospholipids
Authors: Glantz Spencer T. , Berlew Erin E. , Jaber Zaynab , Schuster Benjamin S. , Gardner Kevin H. , Chow Brian Y.
Published: July 2018

Significance

Light–oxygen–voltage (LOV) domain photoreceptors are found ubiquitously in nature and possess highly diverse signaling roles and mechanisms. Here, we show that a class of fungal LOV proteins dynamically associates with anionic plasma membrane phospholipids by a blue light-switched electrostatic interaction. This reversible association is rapidly triggered by blue light and ceases within seconds when illumination ceases. Within the native host, we predict that these proteins regulate G-protein signaling by the controlled recruitment of fused regulator of G-protein signaling (RGS) domains; in applied contexts, we anticipate that engineered chimeric versions of such proteins will be useful for rapid optogenetic membrane localization of fused proteins through direct interaction with the membrane itself, without requiring additional components to direct subcellular localization.