bluuebunny/crossref_metadata_2025 huggingface dataset:
Research on grade evaluation of green urbanization based on cloud matter element model
Authors: Jia Wei , Liu Bing , Ding Wei , Li Hui
Published: September 2018

In the important transition period of urbanization development in China, the concept of “green development” was integrated into the current urbanization research. This paper constructs the grade evaluation index system from six dimensions: population employment, economic development, urban construction, residents' life, social development and ecological development, and combines the cloud model with the matter element model to construct the green urbanization cloud element material model. We took Shandong Province as an example and evaluated the current level of green urbanization in 17 cities by using this model. The results showed that the green urbanization levels of the four cities such as Ji'nan and Qingdao are the highest; the green urbanization levels of the nine cities such as Zibo and Weifang are good; the green urbanization levels of the four cities such as Zaozhuang and Heze are low. Through analysis, the evaluation results of the green urbanization cloud element matter model are objective and accurate, which verifies the rationality of using this model to evaluate the level of green urbanization, and improved the theoretical research of the current green urbanization. In practice, we can provide scientific guidance for the future development of green urbanization in cities to promote the healthy development of China's green urbanization.
Key Technologies for Green, Low-Carbon and Energy-Saving Buildings in Financial Street Chang 'an Center
Authors: Qing Chen , Yuqi Zhou , Yong Huang , Bo Li , Shiyu Zhang
Published: September 2018

Through the innovation and application of eight key technologies for green, low-carbon and energy-saving buildings， Financial Street Chang 'an Center has become the first project in Beijing to obtain the dual certification of three-star green building and LEED gold building, which has played a good demonstration role in the construction of green buildings of urban complex type.
Not every dipole is the same: the hidden patterns of dipolar near fields
Authors: Picardi Michela F. , Zayats Anatoly V , Rodríguez-Fortuño Francisco J.
Published: September 2018

Nanophotonics is a fast-evolving scientific field studying light at the nanoscale. Its fascinating advances typically stem from concepts in modern physics, such as quantum optics, photonic crystals and optomechanics [1]. Occasionally, new insights appear even from the classical Maxwell’s equations of electromagnetism themselves [2].
The early catfish catches the worm: predation of Corydoras aeneus (Siluriformes, Callichthyidae) on freshwater nematodes
Authors: Majdi Nabil , Weber Sebastian , Traunspurger Walter
Published: September 2018

In this study, we measured the daily consumption of four different nematode species by a small freshwater catfish species, Corydoras aeneus (Gill, 1858). Consumption of nematodes by fishes was significant with a single C. aeneus individual being able to consume in 24 h between 40 581 and 75 849 adult nematodes depending on the nematode species offered. This represented the ingestion of up to 238 mg wet weight when considering the largest nematode species: Panagrellus redivivus. Our results strengthen the growing evidence of a significant trophic channel existing between meiobenthic invertebrates like nematodes and small bottom-feeding fishes like C. aeneus. We also discuss the relevance of using P. redivivus as live food for rearing C. aeneus which is a popular ornamental fish.
Greedy heuristics for identical parallel machine scheduling problem with single server to minimize the makespan
Authors: El Idrissi Abdelhak , Benbrahim Mohammed , Benmansour Rachid , Duvivier David
Published: September 2018

This paper considers the problem of scheduling a set of n independent jobs on m identical parallel machines with setup times constraints. Immediately before processing, each job must be loaded on a common server to perform the setup operation. During the loading operation, both the machine and the server are occupied. Two greedy heuristics are developed for (m ≥ 2) in order to minimize respectively the server waiting time and the machine idle time. These heuristics generalize those proposed in the literature for the case of two machines. The computational results show the efficiency of the proposed heuristics.
A Game Theoretic Approach to Analyse Security between Smart Vehicles and Parcels in Smart Cities
Authors: Abdellaoui alaoui El Arbi , El Moudden Mustapha
Published: September 2018

The Internet of Things (IoT) is considered as a modern concept that will revolutionize the near future. Its interest is to create an environment of combined intelligent devices and systems, communicating with each other through wireless networks. Urban logistics are an applicative field of this new technology, especially for smart parcels and vehicles. Actually, in the context of economy development, the competitiveness between companies and territories necessarily involves an improvement of logistics services. Although these gains offered by IoT, there are significant obstacles to counter. One of the important obstacles to consider is the security. In this paper, we will analyze the interaction between selfish smart vehicles/parcels and malicious smart vehicles/parcels, that was formulated as a game model. As a result, we have calculated the Nash equilibrium and the utilities for the both selfish smart vehicles/parcels and malicious smart vehicles/parcels, evaluated the parameters that can maximize the selfish smart vehicles/parcels’s utility when the smart parcels are transported by vehicles between different centers (shops, supermarket, etc) was planned and identify the potential malicious smart vehicles/parcels.
Challenges of cloud computing use: A systematic literature review
Authors: M’rhaoaurh Ibtissam , Okar Chafik , Namir Abdelwahed , Chafiq Nadia
Published: September 2018

Background: In recent years, cloud computing has grown vastly. Cloud computing represents a new model for IT service delivery and it typically provides over-a-network, ondemand, self-service access, which is dynamically scalable and elastic, using pools of often virtualized resources. However, this new paradigm is facing diverse challenges from many fronts. Methods: We conducted a systematic literature review of potential challenges of cloud computing. Documents that described challenges of cloud computing were collected of routinely. We grouped identified challenges in taxonomy for a focused international dialogue on solutions. Results: Twenty-three potential challenges were identified and classified in three categories: policy and organizational, technical and legal. The first three categories are deeply rooted in well-known challenges of cloud computing. Conclusions: The simultaneous effect of multiple interacting challenges ranging from technical to intangible issues has greatly complicated advances in cloud computing adoption. A systematic framework of challenges of cloud computing will be essential to accelerate the use of this technology for working well in fact and in order to face with respect to mitigating IT-related cloud computing risks.
Design and sizing of a Hybrid PV-Wind-Grid System for Electric Vehicle Charging Platform
Authors: Anoune Kamal , Bouya Mohsine , Astito Abdelali , Abdellah Abdellatif Ben
Published: September 2018

The recent technological advancement in the power electronics converters, control, and battery technology, allowed the enhancement of the use of the electric vehicle (EV) as a means of transportation, EV requires to be charged with an electrical grid which imposes an extra burden on the electrical supply during the peak demand duration. The use of renewable energy sources (RES) such as solar and wind remains as alternative sources to reduce this negative impact. The main interest of this work is integrating the RES in transportation systems through a smart grid system with a proposed design of a hybrid PV-Wind-Grid charging platform for EV.
A literature review on multi-echelon inventory management: the case of pharmaceutical supply chain
Authors: Sbai Nouçaiba , Berrado Abdelaziz
Published: September 2018

Inventory management remains a key challenge in supply chain management. Many companies recognize the benefits of a good inventory management system. An effective inventory management helps reaching a high customer service level while dealing with demand variability. In a complex supply chain network where inventories are found across the entire system as raw materials or finished products, the need for an integrated approach for managing inventory had become crucial. Modelling the system as a multi-echelon inventory system allows to consider all the factors related to inventory optimization. On the other hand, the high criticality of the pharmaceutical products makes the need for a sophisticated supply chain inventory management essential. The implementation of the multi-echelon inventory management in such supply chains helps keeping the stock of pharmaceutical products available at the different installations. This paper provides an insight into the multi-echelon inventory management problem, especially in the pharmaceutical supply chain. A classification of several multi-echelon inventory systems according to a set of criteria is provided. A synthesis of multiple multi-echelon pharmaceutical supply chain problems is elaborated.
Multi-Objective Decision Aid Application for RFID Network Planning
Authors: Raghib Abdelkader , Abou El Majd Badr
Published: September 2018

The Radio Frequency Identification system (RFID) is a generic term for technologies of a type of automatic identification system that use radio-frequency waves to automatically identify people or objects. Multiple RFID readers are required to detect and monitor the tags in the network area due to their limited interrogation range. Therefore, the cost of the RFID System, its efficiency in the communication process, and the number of tags covered directly depend on the number of deployed readers. In this work, we present a new many/multi-objective model with the aim to achieve the optimal solutions of the NP-hard problem of RFID Network Planning (RNP). The model involves many objectives and constraints as determining the minimum number of readers, finding their optimal 3D deployment and localization, guarantying a full coverage of all the tags distributed in the area, and minimizing the energy and the interferences caused by an overlap in the readers signals and the tags responds at the same time. Moreover, we provide a new decision aid application with the aim to access, manage, solve, and optimize the RNP problem involving the needs of researchers and decision makers.
The influence of organizational culture on performance: Case study of the Moroccan ATM system
Authors: Ghalem Âta , Okar Chafik , Chroqui Razane , Semma El Alami
Published: September 2018

According to Ferreira and Otley (2009) contextual factors and organizational culture are considered as variable factors that have a significant impact on the performance management system framework, which comprises 12 questions/issues. The intention of this work is to define how organizational culture influences the question/issue of performance information use, through the example of Air Traffic Management (ATM). In fact, based on Schein’s model we determine how two of the levels of organizational culture influence the performance information use within the Moroccan ATM system.
Sensitivity Study of Polysilicon Nanowire Based on Scattering and Quantum Mechanics Models
Authors: Aanand  , Sheu Gene , Imam Syed Sarwar , Lu Shao Wei , Yang Shao-Ming , Fan Ming Jen
Published: September 2018

In this paper, we report nanowire drain saturation current sensitivity property to measure femtomol level change in drain current due to different proteins i.e. DNA with numerical simulation and fabricated polysilicon nanowire based on the theoretical predictions. In addition, the drain current will also be affected by the back-gate voltage and will increase as the back-gate voltage increases. A 3-dimensional Synopsis tool is used to investigate the drain current behavior for a polysilicon nanowire. The scattering compact model reported result of detailed numerical calculation shows in good agreement, indicating the usefulness of scattering compact model. Whereas 3D synopsis unable to explain the whole region of the drain current characteristics in linear region which uses quantum mechanics model approach.
Damage Assessment of a Structure by Using Frequency Responses Function Curvature Method and Cubic Spline Interpolation
Authors: Su Wei-Chih , Huang Chiung-Shiann
Published: September 2018

This study explores the possibility of using frequency responses function curvature method and cubic spline interpolation to locate the storeys of a building that is damaged in an earthquake, and corresponding frequency responses function curvature of storey often change in the earthquake. The frequency responses function of a building in each floor is established from the full structural dynamic responses. Next, the frequency responses function of storeys that be obtained by cubic spline interpolation would be used to detect the damage location of a building. The effectiveness of the proposed procedure is verified using numerically simulated earthquake responses of the finite element model of an eight-storey frame.
Structural Damage Assessment by Using Stiffness-based Method and Cubic Spline Interpolation
Authors: Su Wei-Chih , Huang Chiung-Shiann , Wu Jyh-Horng
Published: September 2018

This study explores the possibility of using stiffness-based method and cubic spline interpolation to locate the damaged storey of a building during a strong earthquake, and corresponding stiffness matrix of structure often change in the earthquake process. The time series model of a building is established from the full structural dynamic responses. Next, the coefficient matrix of the time series model could be solved by recursive least squares (RLS) algorithms. Then, the model parameters of a building are calculated by the coefficient matrix of time series model. Finally, the identified natural frequencies and mode shapes of structure that corrected by cubic spline interpolation would be used to construct the stiffness matrix of a building. Then, the damage location of a building could be detected by the identified stiffness matrix of a building. The effectiveness of the proposed procedure is verified using numerically simulated earthquake responses of the finite element model of a six-storey frame.
Simulation study on the effects of humidity reduction regulation and detection on indoor temperature comfort
Authors: Wang Wen.-An. , Tung Ssu.-Wei.
Published: September 2018

This study would discuss about the installation of indoor smart monitoring and control system and propose a feasible structure to establish a smart system for sensing and controlling the temperature and humidity inside the building. The sensor offers the capability of learning and automatically controlling the indoor temperature and humidity to automatically adjust the indoor heat environment.
Study of HCI Reliability for PLDMOS
Authors: Deivasigamani Ravi , Sheu Gene , Aanand  , Wei Lu Shao , Sarwar Imam Syed , Lai Chiu-Chung , Yang Shao-Ming
Published: September 2018

In this paper, we demonstrate electrical degradation due to hot carrier injection (HCI) stress for PLDMOS device. The lower gate current and the IDsat degradation at low gate voltage (VGS) and high drain voltage (VDS) is investigated. Hot Electrons, generated by impact ionization during stress, are injected into the gate oxide, creating negative fixed oxide charges and interface-states above the accumulation region and the channel. Increase of the drain-source current is induced by the negative fixed oxide charges. The physical model of the degradation has been proven combining experimental data and TCAD simulations.
A Study on the Application of Electronic Nose Coupled with DFA and Statistical Analysis for Evaluating the Relationship between Sample Volumes versus Sensor Intensity of Agarwood Essential Oils Blending Ratio
Authors: Lias Sahrim , Mohamad Ali Nor Azah , Jamil Mailina , Tolmanan Mohd Shafik Yuzman , Misman Muhamad Afizzul
Published: September 2018

The exquisite agarwood oils are primary used for perfumery industries either as pure essential oils or in a perfume base. Commonly, Agarwood oils are extracted from low grade 100% agarwood chips via distillation processes and the extracted oil is called as pure agarwood essential oil which containing 100% of extracted material. In perfumery industry, the agarwood pure oils are often blend with other essential oils such as geranium, sandalwood, gurjum balsam, jasmine and Ylang ylang to create rich, complex and pleasant oils compared to pure Agarwood oils smell alone that may not suit all users preferences. To dates, agarwood oil quality assessment is typically carried out manually via human olfactory system which produces different results and inconsistency from traders and buyers. From the results, multiple linear regression analysis used to run the multiple regression prediction models using combination of 11 sensors shown better results by increasing the R2 value from 0.674 to 0.915 and the RMSE value from 14.65% to 6.80% compared to single regression prediction models using sensor LY2/G. The sensors intensity values from multiple sensors are showing a strong correlation to the volume of the B1 in the blended samples (M11~M20) as the ratio of B1 is increased.
Node-Gosper Island-Based Data Collection Method with Recharge Plan for Rechargeable Wireless Sensor Networks
Authors: Chen Chi-Chang
Published: September 2018

Because of recent advances in wireless power transfer technologies, several key topics of wireless sensor networks (WSNs) need to be revisited. Traditional data collection methods for WSNs typically consider the balance of power consumption among sensors as a critical design criterion for avoiding uneven power depletion in the networks. I propose a solution for the uneven power consumption problem of data collection over WSNs. I designed a node-Gosper island-based scalable hierarchical cluster transmission method in conjunction with a wireless recharge plan for data collection over rechargeable WSNs. For the recharge plan, I used a mobile wireless charger to visit and recharge the batteries of sensors located on different levels of node-Gosper curves with various frequencies. The duration of each recharging process for each layer of sensors was calculated to verify the feasibility of the proposed recharge plan. The simulation results indicate that my proposed data collection method outperforms several well-known data collection methods in terms of energy consumption.
Applying Design Thinking Process in Student’s Project: A case of EGF Products
Authors: Yang Chun-Ming , Man Hong-Thien T.
Published: September 2018

Design thinking process is best known as an effective, human-centred approach to more creative problem solving. This method has been applied as an innovative solution generation technique not only for designers but in other disciplines as well. While Epidermal Growth Factor (EGF) is an important growth factor in human body. It plays a crucial role in recent biological researches for many health-care applications. This study incorporated the design thinking process in EGF application products, aims to encourage student designers to embark on this freshly new problem-solving methodology in biological application, and hope to help introduce new medical products in daily life. Two cases as the results came out from the hands-on class project were also presented.
Analysis of Anti-JFET for 600V VDMOS and HCI Reliability
Authors: Yang Shao-Ming , Sheu Gene , Lai Chiu-Chung , Deivasigamani Ravi
Published: September 2018

In VDMOS device the anti-JFET concentration has important role for determining the breakdown voltage and on-resistance of the device. Because higher N-drift doping concentration can provide the very best on-resistance of the device but also decrease breakdown voltage. It also has a proportional relationship with threshold voltage degradation. In this paper, we report the anti-JFET implantation energy influence effect electric potential distribution, the highest impact ionization shifted from the silicon surface to deeper. It will have less hot carrier impact, and we have found higher breakdown voltage. The anti-JEFT implantation is critical for on-resistance off-state breakdown voltage optimization, However the high field and high impact ionization near the gate region will cause severe hot carrier Injection problem. The general expectation of high voltage VDMOS transistor is to have higher breakdown voltage, less degradation due to hot carrier injection and better on-resistance.
Using AdaBoost-based Multiple Functional Neural Fuzzy Classifiers Fusion for Classification Applications
Authors: Jhang Jyun-Yu , Lee Chin-Ling , Lin Cheng-Jian , Lin Chin-Teng , Young Kuu-Young
Published: September 2018

In this study, two intelligent classifiers, the AdaBoost-based incremental functional neural fuzzy classifier (AIFNFC) and the AdaBoost-based fixed functional neural fuzzy classifier (AFFNFC), are proposed for solving the classification problems. The AIFNFC approach will increase the amount of functional neural fuzzy classifiers based on the corresponding error during the training phase; while the AFNFC approach is equipped with a fixed amount of functional neural fuzzy classifiers. Then, the weights of AdaBoost procedure are assigned for classifiers. The proposed methods are applied to different classification benchmarks. Results of this study demonstrate the effectiveness of the proposed AIFNFC and AFFNFC methods.
Internal defect structure of calcium doped magnesium oxide nanoparticles studied by positron annihilation spectroscopy
Authors: Das A. , Mandal A. C. , Roy S. , Nambissan P. M. G.
Published: September 2018

Calcium-ion substitution to different concentrations in the normally insulating but wide band gap semiconductor magnesium oxide nanocrystallites was successfully achieved through a sol-gel route and the synthesized samples were characterized by X-ray diffraction and transmission electron microscopy. The substitution of Mg2+ by Ca2+ gave rise to distinct variation in the nanocrystallite sizes and lattice constants. The band gap energies (Eg = 5.04 to 5.50 eV) obtained from ultra-violet and visible absorption spectroscopy hinted to the formation of Positronium Hydrogen (Ps-H) complex within nanocrystallites. Excitonic energy levels reduced the band gap after doping. In the samples of larger nanocrystallites, strong evidences to the presence of very large vacancy clusters were observed. The coincidence Doppler broadening measurements also indirectly supported this interpretation. The lineshape and wings parameters also supported the type of defects as evidenced from lifetime measurements. The results appeared significant from the context of choosing doping as an efficient way of molding the properties of semiconductor oxide nanocrystals as concomitant lattice parameter variations and the evolutions of vacancy type defects can significantly alter the expected physical changes towards other directions.
Bulk transport properties of bismuth selenide thin films grown by magnetron sputtering approaching the two-dimensional limit
Authors: Sapkota Yub Raj , Mazumdar Dipanjan
Published: September 2018

Transport properties of topological insulator Bi2Se3 thin films are investigated with an emphasis on understanding finite-size effects as the two-dimensional limit is approached. Ultra-smooth, (000l)-orientated Bi2Se3 thin-films fabricated using radio-frequency magnetron sputtering reveal disproportionately large changes in bulk resistivity and Hall mobility below six quintuple layers (QL). We correlate such changes to the bulk (other than surface) electronic structure where a bandgap enlargement is observed below six QL in optical absorption spectroscopy measurements. This effect is strongest at the three and two quintuple layers that show the largest changes in bandgap. Temperature dependent transport measurements reveal the effect of disorder from substrate and high carrier concentration. Films on sapphire substrate demonstrate better transport properties compared to amorphous quartz. While temperature dependence of bulk resistivity is both thickness and substrate sensitive, the temperature dependence of Hall coefficient is determined only by the carrier concentration in films. Our work highlights the influence of the bulk electronic structure on the transport properties of few-layer Bi2Se3 which is of interest in the applied areas of optoelectronics, nanoelectronics, and spintronics.
Investigation of the prebreakdown stage of the self-sustained subnanosecond discharge in high pressure nitrogen
Authors: Ivanov S. N. , Lisenkov V. V.
Published: September 2018

The results of the investigations of the prebreakdown stage of the self-sustained subnanosecond discharge in nitrogen at pressures between 5 and 40 atm are presented. A high voltage pulse with a front of approximately 250 ps at the level of 0.1–0.9 in amplitude (full duration of the pulse front was 500 ps) was applied to the studied gas gap. In this case, the voltage rise rate in the discharge gap at the prebreakdown stage reached up to 7 × 1014 V/s. Breakdown occurs at the front of the voltage pulse. During these experiments, the parameters of the voltage pulse at the output of the pulse generator were not modified. In this study, it was discovered that increasing of the pressure from 5 atm to 40 atm leads to a significant decrease in the overvoltage in the discharge gap. It is shown that at pressures above 10 atm, the delay time of breakdown is less than the time of growth for electron avalanches to reach a critical size. The critical length of avalanche is approximately one order of magnitude less than the length of the discharge gap. Hence, the avalanche-streamer model is inapplicable in this situation. A mechanism of subnanosecond breakdown initiation with a help of runaway electrons at pressures above 10 atm has been suggested.
Application of spectral-focusing-CARS microscopy to pharmaceutical sample analysis
Authors: Porquez J. G. , Slepkov A. D.
Published: September 2018

We implement spectral-focusing-CARS hyperspectroscopy to characterize pharmaceutical samples. The use of a dynamically-power-tuned supercontinuum seeding method combined with epi-detection of the CARS signals allows for broadband hyperspectroscopy and rapid single vibrational frequency imaging with microsecond pixel dwell times. The broad hyperspectral capabilities spanning about 3000 cm-1 of vibrational information allow for facile discrimination between ibuprofen, common polymorphs of acetaminophen, and starchy binders. Application of 3-D hyperspectral imaging on bare tablet forms reveals surface-bound processing of low-dose drugs such as cetirizine.
Enhancing the modulation depth of a dynamic terahertz metasurface by integrating into an asymmetric Fabry-Pérot cavity
Authors: Lee Gyejung , Nouman Muhammad Tayyab , Hwang Ji Hyun , Kim Hyun-Woong , Jang Jae-Hyung
Published: September 2018

The modulation capability of a terahertz dynamic metasurface was enhanced by integrating it with an asymmetric Fabry-Pérot cavity. The dynamic metasurface consists of split ring resonators combined with high frequency metal semiconductor metal varactors. Integrating the above dynamic metasurface into an asymmetric Fabry-Pérot cavity results in a modulation performance improvement of up to 3.3 times. An analytical model based on transmission line theory illustrates the modulation enhancement mechanism, and provide guidelines for designing dynamic metamaterial devices based on cavity structures.
Relative intensity calibration of the DIII-D charge-exchange recombination spectroscopy system using neutral beam injection into gas
Authors: Grierson B. A. , Burrell K. H. , Chrystal C. , Haskey S. R.
Published: September 2018

A new calibration method for the DIII-D charge-exchange spectroscopy system produces a smoother impurity density profile compared to previous techniques, improving the accuracy of the impurity density profile reconstruction. The relative intensity calibration between the chords of the DIII-D charge-exchange recombination spectroscopy system is performed by firing neutral beams into the evacuated vacuum vessel pre-filled with neutral gas. Relative calibration is required in order to account for uncertainty in the 3D geometry of the neutral beam. Previous methods using helium gas have been improved by using xenon, which emits an emission line close to the commonly used carbon wavelength 5290.5 Å, as well as improved timing of the gas injection, inclusion of variations in the vessel pressure, and timing of neutral beam injection. Photoemission spectra recorded by 112 sightlines viewing 6 neutral beams are compared and used to form a relative calibration factor for each sightline. This relative calibration is shown to improve the quality of the measured ion density profile.
High anisotropy on epitaxial C-doped Mn5Ge3 thin films grown on Ge(001)
Authors: Olive-Méndez Sion F. , López Antón Ricardo , Ponce-Ruiz Jesús L. A. , Holguín-Momaca José T.
Published: September 2018

Epitaxial Mn5Ge3C0.6 thin films were grown on Ge(001) substrates by magnetron sputtering utilizing the reactive deposition epitaxy method at 623 K. The c-axis of the hexagonal crystalline structure of Mn5Ge3 lies in the film plane with the epitaxial relationship Ge(001)[110]∥Mn5Ge3(012)[011]. The film exhibits a large in-plane magnetic anisotropy ten times larger than that observed on Mn5Ge3C0.6 thin films grown on Ge(111) substrates attributed to the double contribution of magnetocrystalline and shape anisotropies. The magnetization M-H curves indicate that the easy magnetization axes lie in the film plane independent of the selected azimuthal, while the normal to the film plane is a hard axis. The films exhibit a ferromagnetic behavior with a Curie temperature of 425 K. Epitaxial Ge(001)/Mn5Ge3C0.6 is therefore proposed as a promising functional material for spintronic applications, which could be directly integrated into the Si technology.
Electron paramagnetic resonance and optical absorption study of acceptors in CdSiP2 crystals
Authors: Scherrer E. M. , Halliburton L. E. , Golden E. M. , Zawilski K. T. , Schunemann P. G. , Hopkins F. K. , Averett K. L. , Giles N. C.
Published: September 2018

Cadmium silicon diphosphide (CdSiP2) is a nonlinear material often used in optical parametric oscillators (OPOs) to produce tunable laser output in the mid-infrared. Absorption bands associated with donors and acceptors may overlap the pump wavelength and adversely affect the performance of these OPOs. In the present investigation, electron paramagnetic resonance (EPR) is used to identify two unintentionally present acceptors in large CdSiP2 crystals. These are an intrinsic silicon-on-phosphorus antisite and a copper impurity substituting for cadmium. When exposed to 633 nm laser light at temperatures near or below 80 K, they convert to their neutral paramagnetic charge states (SiP0 and CuCd0) and can be monitored with EPR. The corresponding donor serving as the electron trap is the silicon-on-cadmium antisite (SiCd2+ before illumination and SiCd+ after illumination). Removing the 633 nm light and warming the crystal above 90 K quickly destroys the EPR signals from both acceptors and the associated donor. Broad optical absorption bands peaking near 0.8 and 1.4 μm are also produced at low temperature by the 633 nm light. These absorption bands are associated with the SiP0 and CuCd0 acceptors.
Rotational dynamics of colloidal hexaferrite nanoplates
Authors: Eliseev Artem A. , Eliseev Andrei A. , Trusov Lev A. , Chumakov Andrei P. , Boesecke Peter , Anokhin Evgeny O. , Vasiliev Alexander V. , Sleptsova Anastasia E. , Gorbachev Evgeny A. , Korolev Vladimir V. , Kazin Pavel E.
Published: September 2018

Here, we report an experimental study on the rotational dynamics of hard magnetic hexaferrite nanoparticles in water. A stable aqueous colloid of SrFe12O19 was synthesized by the borate glass-ceramic dissolution technique and studied by TEM, small-angle X-ray scattering (SAXS), magnetometry, and optical transmission methods in applied DC and AC magnetic fields. The particles represent nanoplates with a mean diameter of 50 nm and a mean thickness of 5 nm having a coercive force of 4700 Oe and a saturation magnetization of 51.5 emu/g. According to magnetic field dependent SAXS data, a probability orientation function was suggested considering the colloidal particle rotation in the applied field as an activation-free process. The magnetization dynamics of the colloidal rotators was described by an interplay of magnetic torque and drag force in the frame of a non-interacting particle model. At frequencies below 100 Hz, the particles are able to fully rotate after the magnetic field. At higher frequencies, the complete following becomes impossible due to the energy dissipation and the particle movement changes to oscillations around randomly oriented axes. These vibrational axes can be aligned by a strong external permanent magnetic field, causing the coherent particle oscillations and correspondingly the rise of the high-frequency response of the colloid optical transmission. As a result, the efficient magneto-optical light modulation has been achieved at frequencies exceeding 5 kHz, revealing the fastest response rates among known colloidal magneto-optical media.
Co-optimizing grating couplers for hybrid integration of InP and SOI photonic platforms
Authors: Passoni M. , Floris F. , Hwang H. Y. , Zagaglia L. , Carroll L. , Andreani L. C. , O’Brien P.
Published: September 2018

Grating couplers are widely used optical interfaces in integrated photonics, especially on the Silicon-On-Insulator (SOI) platform. Their design has been optimized for coupling light between a Photonic Integrated Circuit (PIC) and a single-mode fiber, a μlens for free space transport, or even a second PIC in the same SOI platform. In this work, we co-design matching pairs of grating-couplers on distinct SOI and InP photonic platforms for optimized PIC-to-PIC coupling. By matching the scattering strengths of the two grating-couplers, we show that a PIC-to-PIC insertion loss of 3dB can be achieved. We also investigate how the design parameters impact the coupling efficiency and the bandwidth, ending up with a tolerance analysis. The proposed coupling approach between two different waveguide materials has prospective applications for the hybrid-integration of SOI and InP photonic platforms for communication technologies.
Flow past a circular cylinder executing rotary oscillation: Dimensionality of the problem
Authors: Sengupta Tapan K. , Patidar Deepak
Published: September 2018

Computational results for flow past a cylinder, executing rotary oscillation, are presented from the perspective of flow control and drag reduction for bluff bodies. The governing Navier-Stokes equation is solved for Reynolds numbers (Re) of 250–400 using the two-dimensional (2D) stream function-vorticity formulation. Here, we compare the computational results, qualitatively and quantitatively, with experimental results, showing excellent match. Such a successful match between 2D computations and experiments prompted us to investigate the reason with the help of the Taylor-Proudman theorem, which explains the use of the geostrophic assumption used to define atmospheric motion as being 2D. As a consequence, we map the flow domain with equivalent Rossby and Ekman numbers to explain that the flow past a rotationally oscillating cylinder can remain 2D for Re values which are higher than that is known for the stationary cylinder.
Growth and ferroelectric properties of yttrium-doped hafnium oxide/indium-tin oxide polycrystalline heterostructures with sharp and uniform interfaces
Authors: Yamada Hiroyuki , Toyosaki Yoshikiyo , Sawa Akihito
Published: September 2018

We report on the growth of polycrystalline yttrium-5%-doped HfO2 (YHO) films with sharp and uniform interfaces over a large area on indium-tin oxide (ITO) layers and their ferroelectric properties. On substrates of thermally oxidized silicon, YHO/ITO bilayers were deposited in amorphous form by means of pulsed-laser deposition and were subsequently crystalized by two-step post-deposition annealing (PDA) at low and high temperatures. The crystallized YHO/ITO heterostructures had ultraflat surfaces: atomic-force-microscopy images exhibited a root-mean-square roughness of 0.15 nm over an area of 100 μm2. The roughness was much smaller than that of single-component polycrystalline films of ITO. X-ray diffraction and transmission electron microscopy (TEM) suggested the formation of YHO in higher symmetry phases including ferroelectric orthorhombic (o) YHO. TEM also confirmed crystallization of YHO layers in a pseudo-coherent manner from the YHO/ITO interfaces and resultant sharp and uniform YHO/ITO interfaces. These results are attributable to good lattice matching between the o-YHO layer and the ITO layer. It is suggested that this lattice matching was realized by the reduction of ITO during the crystallization in the two-step PDA process. The reduction might occur in the vicinity of the YHO/ITO interface via H2O incorporated in the amorphous bilayers. Pt/YHO/ITO junctions fabricated by using the two-step PDA method showed a polarization–electric field (P–E) hysteresis loop with remanent polarizations (Pr) of no less than 13 μC/cm2 at YHO thicknesses of 12 and 6 nm. These results indicate that the two-step PDA method can be used to fabricate high-quality YHO/ITO heterostructures in terms of surface and interface morphology, as well as ferroelectric properties.
Dynamics of three-layer convection in a two-dimensional spherical domain with a growing innermost layer: Implications for whole solid-earth dynamics
Authors: Yoshida Masaki
Published: September 2018

I have performed numerical simulations of thermal convection with a highly viscous outermost layer (HVL), low-viscosity middle layer (LVL), and highly viscous innermost layer (IML) growing with time in a 2-D spherical domain. The results show that the average temperature of the LVL significantly decreases and the root-mean-square velocity of the LVL fluctuates significantly when the IML grows with time, compared to the model without the growing IML. This result suggests that the formation of the IML cools the LVL effectively. However, the existence of the growing IML barely affects the magnitude and spatial pattern of the heat flow at the HVL–LVL interface and the convection pattern of the HVL. In addition, the growing IML lengthens the lateral scale of the LVL convection owing to the basal heating from the LVL–IML interface. The present numerical results imply that the growing inner core, which corresponds to the IML in this model, throughout the Earth’s history may barely affect the convection pattern of the mantle (HVL) and the heat flow escaping from the outer core (i.e., LVL) to the mantle via the core–mantle boundary (i.e., the HVL–LVL interface). A previous geodynamo simulation suggested that the lateral thermal heterogeneity of the temperature just under the core–mantle boundary strengthens the geomagnetic field in the outer core. The present numerical results may suggest that the growing inner core throughout the Earth’s history facilitates the strong lateral thermal heterogeneity and strengthens the geomagnetic field.
Introduction.
Authors: Kelanaputra E. S. , Nelson S. P. C. , Setiawati U. , Sitepu B. , Nur F. , Forster B. P. , Purba A. R.
Published: September 2018

Oil palm, EIaeis guineensis Jacq., is an important source of vegetable oil. Oil is extracted from the fruit mesocarp (crude palm oil) and from the seed (palm kernel oil). Botanically, the fruit is a drupe, with the kernel protected by a shell (nut). The commercial oil palm is Tenera (thin shelled), which is a hybrid from crossing Dura (thick shelled) seed palms with Pisifera (no shell) pollen palms. Since the shell is maternal tissue, seed for commercial planting has a thick shell. Like most seeds with very thick shells, oil palm seeds are difficult to germinate, the seed naturally germinates sporadically over time, and dormancy can last for up to 2 years. The challenges for seed production are to overcome dormancy (by weakening the operculum to allow germination), synchronize germination, produce a high germination percentage and high-quality germinated seed, free of abnormality or fungal infection. The processes used involve temperature treatments, imbibition, adjustment of seed moisture content and fungal control.
Isolation of the female inflorescence.
Authors: Kelanaputra E. S. , Nelson S. P. C. , Setiawati U. , Sitepu B. , Nur F. , Forster B. P. , Purba A. R.
Published: September 2018

Care is required when isolating female inflorescences to prevent damage. The developing inflorescence should be treated with insecticides to prevent insects, particularly the oil palm-pollinating weevil, from leading to pollen cross-contamination. Specialized isolation bags are designed with a window to inspect and monitor development and through which subsequent operations (spraying and pollination) are performed. The isolation process involves insect-proofing as insects, particularly weevils, carry unwanted pollen and cause seed contamination. Instructions are given on the procedures used in isolating the female inflorescence that maximize success in artificial crossing. The procedures involve the use of hazardous chemicals (insecticides) and may involve climbing tall palms. Guidance in health and safety procedures are given in Chapter 2 of this manual.
Pollination.
Authors: Kelanaputra E. S. , Nelson S. P. C. , Setiawati U. , Sitepu B. , Nur F. , Forster B. P. , Purba A. R.
Published: September 2018

Pollination is controlled through a window in the specialized isolation bag; this reduces the risk of contamination (foreign pollen, disease and insects). Prior to pollination, the area around the isolation bag is sprayed to kill insects, as these can carry unwanted pollen. Pollen is normally mixed and diluted with talcum powder to provide an inert spreading media. This mixture is blown on to receptive female inflorescences using a surface-sterilized 'popper' that has a tube containing silica gel to adsorb the moisture from the pollinator's breath. The isolation bag is also shaken to spread the pollen over the entire inflorescence. Labels are then attached showing pollination dates and parental genotypes. The isolation bags may be removed once fruit set is established and harvested when fruits are mature.
Harvesting.
Authors: Kelanaputra E. S. , Nelson S. P. C. , Setiawati U. , Sitepu B. , Nur F. , Forster B. P. , Purba A. R.
Published: September 2018

The ripe bunch with red-coloured fruits can be harvested about 150 days after pollination, or when one loose fruit appears on the ground. Harvested bunches are sent to the processing area in gunny sacks, along with any loose fruit that detach during harvesting. Minimum ripeness standards are used to reduce the risk of loose fruit/seed being lost, and the use of net bags after bag removal at 21-25 days post-pollination will prevent any loose fruit loss.
Seed processing for commercial production.
Authors: Kelanaputra E. S. , Nelson S. P. C. , Setiawati U. , Sitepu B. , Nur F. , Forster B. P. , Purba A. R.
Published: September 2018

Oil palm seeds have sessile embryos and, for germination to start, the operculum that blocks the germ pore (and essentially makes the seed dormant) has to be weakened. Seed processing procedures must be implemented and monitored to ensure maximum and uniform germinations are achieved; the usual commercial target is over 80%.
Pollination.
Authors: Setiawati U. , Sitepu B. , Nur F. , Forster B. P. , Dery S.
Published: September 2018

Pollination is effected through a window in the specialized isolation bag. This reduces the risk of contamination (pollen, disease and insects). Prior to pollination, the area around the isolation bag is sprayed to kill insects, as these can carry unwanted pollen. Pollen is normally mixed and diluted with talcum powder to provide a volume easy to handle. This mixture is blown on to receptive female inflorescences using specialized equipment that has been surface sterilized. The isolation bag is also shaken to spread the pollen over the entire inflorescence. Labels are then attached showing pollination dates and parental genotypes. The isolation bags may be removed once fruit set is established and harvested when fruits are mature. Pollination is normally carried out in the morning, when nectar is visible on female florets. Mature pollen grains of oil palm are binucleate, containing one vegetative and one generative nucleus. When the pollen grain arrives on a receptive stigma of a female inflorescence, it begins to germinate. The pollen tube grows down the style, carrying with it the two nuclei; the generative nucleus divides to produce two sperm cells, which are deposited into the ovary, where they effect fertilization (see Chapter 1, Section 1.4 of this manual). For more details on oil palm pollen development, see Nasution et al. (2009).
Commercial Tenera production.
Authors: Setiawati U. , Sitepu B. , Nur F. , Forster B. P. , Dery S.
Published: September 2018

Contemporary oil palm cultivars have a thick, oil-bearing mesocarp and thin-shelled fruits, that is, a Tenera phenotype, and this is controlled genetically by the shell thickness gene, Sh. The Tenera genotype is heterozygous (Sh/sh) and is produced by crossing a thick-shelled female Dura (Sh/Sh) with a no-shell male Pisifera (sh/sh). Commercial production of Teneras needs to be controlled rigorously. Crossing is carried out as described above, but additional measures are taken to ensure purity of the product; these are described below. Dura palms are used as mother palms, and the Pisiferas are used as father (pollen) palms. Pollen from selected commercial father palms is collected on a routine basis and stored ready for use. The crossing process is the same as that described above but may include more rigorous procedures to ensure quality of the commercially produced seed; for example, high pollen viability and legitimacy testing. The seed production programme requires selected Duras and Pisiferas. The Dura selection is based on progeny performance by D × P progeny trials (Forster et al., 2017). The Pisifera selection is based on individual Pisiferas through Pisifera testing trials. Most oil palm seed producers in the world use Deli Duras as mother palms, since they guarantee offspring with superior bunch and fruit characteristics. There are some research stations in Africa that do not use Deli Dura lines as female parents, because the major objectives are to obtain Fusarium oxysporum wilt resistance and drought tolerance.