bluuebunny/crossref_metadata_2025 huggingface dataset:
Light-addressable electrochemistry at semiconductor electrodes: redox imaging, mask-free lithography and spatially resolved chemical and biological sensing
Authors: Vogel Yan B. , Gooding J. Justin , Ciampi Simone
Published: May 2019

Electrochemical reactions in 2D with one electrical lead and a single-channel potentiostat.
Enhanced selectivity of target gas molecules through a minimal array of gas sensors based on nanoparticle-decorated SWCNTs
Authors: Freddi Sonia , Drera Giovanni , Pagliara Stefania , Goldoni Andrea , Sangaletti Luigi
Published: May 2019

Layers of CNTs decorated with metal and metal–oxide nanoparticles can be used to develop highly selective gas sensor arrays.
Electrochemiluminescence of 3,4,9,10-perylenetetracarboxylic acid/oxamic hydrazide and its application in the detection of tannic acid
Authors: Lan Yixiang , Wang Chao , Yuan Fan , Fereja Tadesse Haile , Lou Baohua , Han Shuang , Li Jianping , Xu Guobao
Published: May 2019

The electrochemiluminescence of 3,4,9,10-perylenetetracarboxylic acid/oxamic hydrazide is reported and used for tannic acid detection for the first time.
Synthesis of dual functional gallic-acid-based carbon dots for bioimaging and antitumor therapy
Authors: Lu Shuting , Liu Liping , Wang Henan , Zhao Wancheng , Li Zeyu , Qu Zheng , Li Jialu , Sun Tiedong , Wang Ting , Sui Guangchao
Published: May 2019

Functional gallic acid-based carbon dots (GACDs) exhibited decent imaging effects and anti-cancer activities in vivo.
Cationic axial ligands on sulfur substituted silicon(iv) phthalocyanines: improved hydrophilicity and exceptionally red-shifted absorption into the NIR region
Authors: Furuyama Taniyuki , Ishii Takashi , Ieda Naoya , Maeda Hajime , Segi Masahito , Uchiyama Masanobu , Nakagawa Hidehiko
Published: May 2019

Herein, we report the exceptionally red-shifted absorption of sulfur-substituted silicon(iv) phthalocyanines upon introduction of cationic axial ligands.
A convenient access to allylic triflones with allenes and triflyl chloride in the presence of (EtO)2P(O)H
Authors: Ni Jixiang , Jiang Yong , An Zhenyu , Lan Jingfeng , Yan Rulong
Published: May 2019

A simple method for the preparation of allylic triflones from allenes and triflyl chloride in the presence of (EtO)2P(O)H has been developed.
Ultrasensitive and simultaneous determination of RNA modified nucleotides by sheathless interfaced capillary electrophoresis–tandem mass spectrometry
Authors: Yu Yue , Zhu Si-Hao , Yuan Fang , Zhang Xiao-Hui , Lu Yan-Ye , Zhou Ying-Lin , Zhang Xin-Xiang
Published: May 2019

A label-free ultrasensitive method was established for the simultaneous determination of RNA modified nucleotides based on a sheathless capillary electrophoresis–tandem mass spectrometry system and successfully applied to investigate the effects of exposure to nickel ions on RNA epigenetics.
Protein film electrochemical EPR spectroscopy as a technique to investigate redox reactions in biomolecules
Authors: Abdiaziz Kaltum , Salvadori Enrico , Sokol Katarzyna P. , Reisner Erwin , Roessler Maxie M.
Published: May 2019

Direct potential control of protein redox centres for both electrochemical and EPR characterisation.
Construction of polycyclic bridged indene derivatives by a tandem 1,3-rearrangement/intramolecular Friedel–Crafts cyclization of propargyl acetates
Authors: Zhang Jiantao , Liao Zhehui , Chen Lianfen , Jiang Huanfeng , Zhu Shifa
Published: May 2019

An unprecedented Lewis acid-catalyzed cascade 1,3-rearrangement/Friedel–Crafts cyclization of propargyl acetates is developed for the construction of polycyclic bridged indene derivatives.
Directed ortho-metalation–nucleophilic acyl substitution strategies in deep eutectic solvents: the organolithium base dictates the chemoselectivity
Authors: Ghinato Simone , Dilauro Giuseppe , Perna Filippo Maria , Capriati Vito , Blangetti Marco , Prandi Cristina
Published: May 2019

Organolithium-mediated chemoselectivity in deep eutectic solvents: basicity vs. nucleophilicity.
LiAl5O8 as a potential coating material in lithium-ion batteries: a first principles study
Authors: Mo Sijia , Zhang Bingkai , Zhang Kecheng , Li Shunning , Pan Feng
Published: May 2019

Coating materials in lithium-ion batteries (LIBs) have attracted extensive attention due to their ability to retard the decay of electrochemical performance in long-term cycling.
The effects of the nature of TiO2 supports on the catalytic performance of Rh–Mn/TiO2 catalysts in the synthesis of C2 oxygenates from syngas
Authors: Yu Jun , Yu Jihang , Shi Zhangping , Guo Qiangsheng , Xiao Xiuzhen , Mao Haifang , Mao Dongsen
Published: May 2019

Four types of TiO2 with different rutile/anatase crystalline phase compositions were used as supports, and the effect of the TiO2 phase composition on the catalytic properties of supported Rh catalysts in the synthesis of C2 oxygenates from syngas was studied.
Preparation, characterization and catalytic performance of rod-like Ni–Nb–O catalysts for the oxidative dehydrogenation of ethane at low temperature
Authors: Kong Lian , Li Dong , Zhao Zhen , Li Jianmei , Zhao Linlin , Fan Xiaoqiang , Xiao Xia , Xie Zean
Published: May 2019

Improved catalytic performance as well as stability over Ni–Nb–O catalysts by hydrothermal method.
Multi-collector ICP-mass spectrometry reveals changes in the serum Mg isotopic composition in diabetes type I patients
Authors: Grigoryan Rosa , Costas-Rodríguez Marta , Van Laecke Steven , Speeckaert Marijn , Lapauw Bruno , Vanhaecke Frank
Published: May 2019

Serum Mg shows a lighter isotopic composition in diabetes type-1 patients than in an age- and gender-matched reference population.
Importance of lipophilicity for potent anti-herpes simplex virus-1 activity of α-hydroxytropolones
Authors: Berkowitz Alex J. , Franson Abaigeal D. , Gazquez Cassals Andreu , Donald Katherine A. , Yu Alice J. , Garimallaprabhakaran Aswin K. , Morrison Lynda A. , Murelli Ryan P.
Published: May 2019

Lipophilic side-chains enhance αHT antiviral potency.
Hollow and inward-bumpy gold nanoshells fabricated using expanded silica mesopores as templates
Authors: Kim Joon Ki , Jang Du-Jeon
Published: May 2019

Hollow and inward-bumpy Au nanoshells showing efficient Raman enhancement have been fabricated using expanded silica mesopores as templates.
An array of SiGe nanodisks with Ge quantum dots on bulk Si substrates demonstrating a unique light–matter interaction associated with dual coupling
Authors: Zhang Ningning , Wang Shuguang , Chen Peizong , Zhang Lijian , Peng Kun , Jiang Zuimin , Zhong Zhenyang
Published: May 2019

An array of SiGe nanodisks with Ge quantum dots is realized directly on bulk Si substrates, demonstrating a unique light–matter interaction.
Metallic 1T-phase MoS2 quantum dots/g-C3N4 heterojunctions for enhanced photocatalytic hydrogen evolution
Authors: Liang Zhangqian , Sun Benteng , Xu Xuesong , Cui Hongzhi , Tian Jian
Published: May 2019

We prepared metallic 1T-MoS2 QD decorated g-C3N4 NSs by a sonication-assisted hydrothermal method for enhanced photocatalytic hydrogen evolution.
A three-dimensional porous Co@C/carbon foam hybrid monolith for exceptional oil–water separation
Authors: Ge Xiao , Qin Wenxiu , Zhang Haimin , Wang Guozhong , Zhang Yunxia , Yu Chengzhong
Published: May 2019

A 3D porous Co@C/CF hybrid monolith and the corresponding oil-collecting device have been successfully fabricated for exceptional oil/water separation.
Accelerated hydrolytic degradation of ester-containing biobased epoxy resins
Authors: Shen Minjie , Almallahi Rawan , Rizvi Zeshan , Gonzalez-Martinez Eliud , Yang Guozhen , Robertson Megan L.
Published: May 2019

Biobased epoxy resins, derived from lignin, phenolic acids, and vegetable oils, exhibited rapid degradation through hydrolysis in basic solution.
Photo-controlled release of metal ions using triazoline-containing amphiphilic copolymers
Authors: Xu Xiaoying , Zhang Qian , Liu Kang , Liu Nailiang , Han Ying , Chen Weixing , Xie Chao , Li Pengfei , He Jie
Published: May 2019

Photo-controlled release of metal ions can be achieved by denitrogenation of triazoline from the micelles of amphiphilic copolymer, and has potential applications for biomedicines.
Side-chain-tuned π-extended porous polymers for visible light-activated hydrogen evolution
Authors: Yu Kaijin , Bi Shuai , Ming Wenyong , Wei Weiwei , Zhang Yinghang , Xu Junsong , Qiang Peirong , Qiu Feng , Wu Dongqing , Zhang Fan
Published: May 2019

Side-chain-tuned conjugated porous polymers with sp2-carbon-linked skeleton feature excellent π-delocalization, narrow band gaps, hydrophilicity and chemical stability, allowing for efficient photocatalytic hydrogen evolution from water splitting.
Diazido platinum(iv) complexes for photoactivated anticancer chemotherapy
Authors: Shi Huayun , Imberti Cinzia , Sadler Peter J.
Published: May 2019

Diazido Pt(iv) complexes with a general formula [Pt(N3)2(L)(L′)(OR)(OR′)] are a new generation of anticancer prodrugs designed for use in photoactivated chemotherapy.
A Sc(OTf)3 catalyzed Mukaiyama–Mannich reaction of difluoroenoxysilanes with unactivated ketimines
Authors: Hu Xiao-Si , Ding Pei-Gang , Yu Jin-Sheng , Zhou Jian
Published: May 2019

The first example of a Mukaiyama–Mannich reaction of difluoroenoxysilanes with unactivated ketimines catalyzed by Sc(OTf)3 is described.
In situ3D nanoscale advanced imaging algorithms with integrated chemical imaging for the characterisation of pharmaceuticals
Authors: Nirwan Jorabar Singh , Conway Barbara R. , Ghori Muhammad Usman
Published: May 2019

Nanoscale chemical imaging technique for simultaneous quantification of swelling, erosion, drug release and 3D surface topography with full surface scanning.
Fixing CO2 into β-oxopropylcarbamates in neat condition by ionic gelation/Ag(i) supported on dendritic fibrous nanosilica
Authors: Chang Liping , Zhiani Rahele , Sadeghzadeh Seyed Mohsen
Published: May 2019

In this research, AgBr supported on an ionic gelation-based nanomaterial, was developed through the aqueous coprecipitation approach for the dendritic fibrous nanosilica (DFNS) production.
An overview on synthetic strategies for the construction of star-shaped molecules
Authors: Diab Hadeer M. , Abdelmoniem Amr M. , Shaaban Mohamed R. , Abdelhamid Ismail A. , Elwahy Ahmed H. M.
Published: May 2019

This review summarizes the strategies for the synthesis of star-shaped molecules as well as their specific syntheses.
Small molecule PROTACs: an emerging technology for targeted therapy in drug discovery
Authors: Pei Haixiang , Peng Yangrui , Zhao Qiuhua , Chen Yihua
Published: May 2019

An overview of the latest developments in PROTAC technology and the possible directions of this approach is presented.
The effect of rhenium on the conversion of glycerol to mono-alcohols over nickel catalysts under continuous flow conditions
Authors: Shozi Mzamo L. , Dasireddy Venkata D. B. C. , Singh Sooboo , Govender Alisa , Mohlala Pheladi , Friedrich Holger B.
Published: May 2019

Incorporation of Re in supported Ni catalysts greatly improves hydrogenolysis of glycerol to mono-alcohols via increased acidity, dispersion and metal–support interaction.
Projected economic outlook and scenario analysis for H2 production by alkaline water electrolysis on the basis of the unit electricity price, the learning rate, and the automation level
Authors: Lee Boreum , Lee Hyunjun , Cho Hyun-Seok , Cho Won-Chul , Kim Chang-Hee , Lim Hankwon
Published: May 2019

A learning curve, a unit electricity price, and an automation level are considered to improve economic feasibility for H2 production by alkaline water electrolysis.
Facile preparation of novel and active 2D nanosheets from non-layered and traditionally non-exfoliable earth-abundant materials
Authors: Liu Sheng , Xie Lei , Qian Hui , Liu Guangyi , Zhong Hong , Zeng Hongbo
Published: May 2019

A facile and versatile route is developed to exfoliate earth-abundant non-layered materials along cleavage orientations into atomically thin sheets.
pH-Responsive reversibly cross-linked micelles by phenol–yne click via curcumin as a drug delivery system in cancer chemotherapy
Authors: Liu Yuancheng , Chen Fan , Zhang Kui , Wang Quan , Chen Yuanwei , Luo Xianglin
Published: May 2019

pH-sensitive reversibly cross-linked micelles by phenol–yne click via curcumin (Cur) using mPEG-b-PHEMA-5HA are developed by combining drug loading and cross-linking as a drug delivery system.
Graphene oxide nanocells for impairing topoisomerase and DNA in cancer cells
Authors: Nandi Aditi , Ghosh Chandramouli , Bajpai Aman , Basu Sudipta
Published: May 2019

We have engineered graphene oxide based nanocell to target DNA topoisomerases and nuclear DNA in cancer cells to induce apoptosis.
Mitochondria targeting two-photon fluorescent molecules for gene transfection and biological tracking
Authors: Sun Wan , Liu Xu-Ying , Cui Jing-Xue , Ma Le-Le , Zhang Yuan , Lu Zhong-Lin , He Lan
Published: May 2019

Mitochondria targeting two-photon fluorescent organic molecules are applied in gene transfection in vitro and in vivo.
DOX-assisted functionalization of green tea polyphenol nanoparticles for effective chemo-photothermal cancer therapy
Authors: Chen Xiangyu , Yi Zeng , Chen Guangcan , Ma Xiaomin , Su Wen , Cui Xinxing , Li Xudong
Published: May 2019

Green tea polyphenol nanoparticles with chemotherapeutic and photothermal performance exhibited effective anti-tumor effects in vivo with intravenous injection.
Construction of highly fluorescent N–O seven-membered heterocyclesviathermo-oxidation of oxazolidines
Authors: Chen Qiaonan , Liang Xiao , Du Jiahui , Wei Zhonglin , Zhang Yu-Mo , Zhang Ting , Qin Tianyou , Gao Wenbin , Sheng Lan , Zhang Sean Xiao-An
Published: May 2019

A controllable heterocyclic construction method to obtain planar structures with multiple fluorescent colors and excellent fluorescence quantum yields.
Mesomorphic and electrooptical properties of viologens based on non-symmetric alkyl/polyfluoroalkyl functionalization and on an oxadiazolyl-extended bent core
Authors: Pibiri Ivana , Beneduci Amerigo , Carraro Mauro , Causin Valerio , Casella Girolamo , Corrente Giuseppina Anna , Chidichimo Giuseppe , Pace Andrea , Riccobono Alessio , Saielli Giacomo
Published: May 2019

Non-symmetric alkyl/polyfluoroalkyl viologens with electrochromism in the smectic phase and mesomorphism of bent core oxadiazolyl viologens with hampered electrochromism.
Green phosphorescent organic electroluminescent devices with 27.9% external quantum efficiency by employing a terbium complex as a co-dopant
Authors: Cui Rongzhen , Liu Weiqiang , Zhou Liang , Zhao Xuesen , Jiang Yunlong , Cui Yingjie , Zhu Qi , Zheng Youxuan , Zhang Hongjie
Published: May 2019

Bright green organic electroluminescent devices with a low operating voltage and high efficiencies were realized by utilizing trivalent rare earth complexes as co-dopants.
Gut microbiota imbalances in Tunisian participants with type 1 and type 2 diabetes mellitus
Authors: Fassatoui Meriem , Lopez-Siles Mireia , Díaz-Rizzolo Diana A. , Jmel Haifa , Naouali Chokri , Abdessalem Ghaith , Chikhaoui Asma , Nadal Belén , Jamoussi Henda , Abid Abdelmajid , Gomis Ramon , Abdelhak Sonia , Martinez-Medina Margarita , Kefi Rym
Published: May 2019

Gut microbiota plays an important role in the regulation of the immune system and host’s metabolism. We aimed to characterize the gut microbiota of Tunisian participants with and without diabetes.

We enrolled ten participants with type 1 diabetes mellitus (T1DM), ten patients with type 2 diabetes mellitus (T2DM), and 11 subjects without diabetes. Bacteria was quantified in fecal samples by quantitative PCR (qPCR). Statistical tests and multivariate analysis were performed using RStudio program.

Results showed that the proportions of Firmicutes, Akkermansia muciniphila, and Faecalibacterium prausnitzii (P≤0.041), as well as, the ratio Firmicutes/Bacteroidetes decreased in participants with T1DM compared with those without diabetes (p = 0.036). Participants with T2DM presented a reduction in the amounts of A. muciniphila and F. prausnitzii compared with those without diabetes (P≤0.036). Furthermore, A muciniphila is negatively correlated with glucose level (P=0.022) and glycated hemoglobin (HbA1c) (P=0.035). Multivariate analysis revealed that participants with diabetes formed a cluster apart compared with those without diabetes.

In conclusion the gut bacteria of Tunisian participants with diabetes was altered. The gut bacterial profile, especially the distribution of A muciniphila in participants with diabetes was affected by glycemic dysregulation. The investigation of the gut microbiota may help clinicians to improve diagnosis and treatment of diabetes and its complications.
Trehalose: is it a potential inhibitor of antithrombin polymerization?
Authors: Martínez-Martínez Irene
Published: May 2019

SERine Protease INhibitorS (Serpins) are a superfamily of proteins that are characterized by having a similar three-dimensional structure. The native conformation is not most thermodynamically stable, so polymerization is the main consequence when its stability is altered as a result of certain mutations. The polymerization of serpins has been a research topic for many years. Different mechanisms have been proposed and in the same way different compounds or strategies have been studied to prevent polymerization. A recent paper published in Bioscience Reports by Naseem et al. [Biosci. Rep. (2019) 5, 39] studies the role of trehalose in the prevention of the polymerization of antithrombin, which belongs to the serpin superfamily. The main consequence of the antithrombin polymerization is the increased thrombotic risk, since antithrombin is the main inhibitor of the coagulation cascade. The authors demonstrate that trehalose is able to prevent the in vitro polymerization of antithrombin, under conditions in which it usually tends to polymerize, and demonstrate it by using different techniques. However, the binding site of trehalose in antithrombin should be defined by site-directed mutagenesis. On the other hand, it is not clear if all serpins polymerize in vivo through the same mechanism and it is also not clear if the same serpin can even polymerize through different mechanisms. Therefore, there are still doubts about the potential of trehalose or its derivatives to prevent in vivo antithrombin polymerization and, therefore, reduce thrombotic risk, as well as whether trehalose would be able to reduce polymerization in other serpins.
A Comparison of Behavioral Methods for Indexing the Auditory Processing of Temporal Fine Structure Cues
Authors: Hoover Eric C. , Kinney Brianna N. , Bell Karen L. , Gallun Frederick J. , Eddins David A.
Published: May 2019

Purpose

Growing evidence supports the inclusion of perceptual tests that quantify the processing of temporal fine structure (TFS) in clinical hearing assessment. Many tasks have been used to evaluate TFS in the laboratory that vary greatly in the stimuli used and whether the judgments require monaural or binaural comparisons of TFS. The purpose of this study was to compare laboratory measures of TFS for inclusion in a battery of suprathreshold auditory tests. A subset of available TFS tasks were selected on the basis of potential clinical utility and were evaluated using metrics that focus on characteristics important for clinical use.

Method

TFS measures were implemented in replication of studies that demonstrated clinical utility. Monaural, diotic, and dichotic measures were evaluated in 11 young listeners with normal hearing. Measures included frequency modulation (FM) tasks, harmonic frequency shift detection, interaural phase difference (TFS–low frequency), interaural time difference (ITD), monaural gap duration discrimination, and tone detection in noise with and without a difference in interaural phase (N0S0, N0Sπ). Data were compared with published results and evaluated with metrics of consistency and efficiency.

Results

Thresholds obtained were consistent with published data. There was no evidence of predictive relationships among the measures consistent with a homogenous group. The most stable tasks across repeated testing were TFS–low frequency, diotic and dichotic FM, and N0Sπ. Monaural and diotic FM had the lowest normalized variance and were the most efficient accounting for differences in total test duration, followed by ITD.

Conclusions

Despite a long stimulus duration, FM tasks dominated comparisons of consistency and efficiency. Small differences separated the dichotic tasks FM, ITD, and N0Sπ. Future comparisons following procedural optimization of the tasks will evaluate clinical efficiency in populations with impairment.
Osteoblast compatibility of 3D printed Co–Cr–Mo alloys with different building direction
Authors: Migita Satoshi , Sakashita Kosuke , Suyalatu
Published: May 2019

Three‐dimensional (3D) metal printing is an attractive technique for fabricating biomedical devices. The microstructures and mechanical properties of the fabricated 3D metal printed products show anisotropy because the grains grow along the z‐axis direction. However, the effects of different printing directions on the cytocompatibility of the products are unknown. In the present study, cobalt–chromium–molybdenum (Co–Cr–Mo) alloy cylinders were fabricated along the z‐axis (vertical) and x‐axis (horizontal), respectively, and the effect of build direction on the cytocompatibility was evaluated. The build direction of 3D printed Co–Cr–Mo alloy changed grain anisotropy; however, there was no statistical difference in grain size. The wettability, protein adsorption, cell attachment, and cell proliferation on the disks of vertical and horizontal products were similar to those on cast alloy; they were significantly lower than those of commercially pure titanium and tissue culture polystyrene. The build direction of 3D printed Co–Cr–Mo alloy does not affect osteoblast compatibility.
Enabling the development of accurate intrinsic parameter extraction model for GaN HEMT using support vector regression (SVR)
Authors: Khusro Ahmad , Hashmi Mohammad S. , Ansari Abdul Quaiyum
Published: May 2019

This study employs support vector regression (SVR) to develop an accurate and reliable intrinsic parameter extraction model for gallium nitride (GaN) high electron mobility transistors (HEMT) using two different geometries of 2 × 200 μm and 4 × 100 µm. The key aspect of the proposed approach is the use of nonlinear Gaussian kernel to transform the input space into a high‐dimensional feature space. It then allows the application of learning technique to develop a reliable procedure for parameter extraction. The proposed extraction model of GaN HEMT has been developed for a broad range of frequency, from 1 to 18 GHz, with multi‐biasing sets for HEMTs of two different geometries. Moreover, the proposed model is made scalable in terms of geometry parameters and therefore can be used to predict the intrinsic parameters and enumerate scaling efficiency of GaN HEMTs by investigating the geometry parameters. A good agreement is observed between the measured S‐parameters and the proposed model for the complete frequency range. It is shown that the proposed approach is simple, novel and can be readily incorporated into computer‐aided design tool for an accurate and expedited design process of RF and microwave circuits.
Measurements and model for the satellite‐to‐aircraft channel in L‐band
Authors: Jost Thomas , Wang Wei , Schwinzerl Martin , Pérez‐Fontán Fernando , Schönhuber Michael , Floury Nicolas , Dimitrov Svilen
Published: May 2019

Wireless radio transmission from a satellite‐based emitter to a receiver located on an aircraft is of interest for many applications such as internet access for passengers, air traffic management or positioning by global navigation satellite systems especially when a worldwide service shall be granted. In particular, the last two mentioned applications are related to the safety of life requiring realistic and accurate channel models for software‐based system testing. State‐of‐the‐art channel models for the satellite‐to‐aircraft case lack of accuracy in terms of modelling all propagation impairments. In this contribution, the authors describe airborne propagation experiments using Global Positioning System signals for channel sounding, the data evaluation and the derived channel model.
Case study on the effects of partial solar eclipse on distributed PV systems and management areas
Authors: Sundararajan Aditya , Olowu Temitayo O. , Wei Longfei , Rahman Shahinur , Sarwat Arif I.
Published: May 2019

Photovoltaic (PV) systems are weather‐dependent. A solar eclipse causes significant changes in these parameters, thereby impacting PV generation profile, performance, and power quality of larger grid, where they connect to. This study presents a case study to evaluate the impacts of the solar eclipse of 21 August 2017, on two real‐world grid‐tied PV systems (1.4 MW and 355 kW) in Miami and Daytona, Florida, the feeders they are connected to, and the management areas they belong to. Four types of analyses are conducted to obtain a comprehensive picture of the impacts using 1 min PV generation data, hourly weather data, real feeder parameters, and daily reliability data. These analyses include: individual PV system performance measurement using power performance index; power quality analysis at the point of interconnection; a study on the operation of voltage regulating devices on the feeders during eclipse peak using an IEEE 8500 test case distribution feeder; and reliability study involving a multilayer perceptron framework for forecasting system reliability of the management areas. Results from this study provide a unique insight into how solar eclipses impact the behaviour of PV systems and the grid, which would be of concern to electric utilities in future high penetration scenarios.
Gas sensor array assisted with UV illumination for discriminating several analytes at room temperature
Authors: Naeimi Pour Mohsen , Nikfarjam Alireza , Taheri Asghar , Sadredini Ahmad Reza
Published: May 2019

In this work, a metal‐oxide gas sensor array was fabricated for discriminating several gases at room temperature using ultraviolet (UV) illumination. The sensor array consisted of four interdigitated gold microelectrodes, and titanium dioxide (TiO2) nanofibres were electrospun on them. The nanofibres were calcined at 550°C for 1 h. Finally, one of these sensors was coated with a thin layer of gold (Au) using DC sputtering method at a thickness of 2 nm. Similarly, the other two sensors were coated with a thin layer of platinum (Pt) and copper (Cu), respectively, and the last one remained uncoated. The nanofibres were characterised by scanning electron microscope, X‐ray diffraction, and UV spectroscopy. The examined analytes were methanol, ethanol, NH3, and acetone, each at seven various concentration levels, including 50, 100, 150, 200, 300, 400, and 500 ppm. Principal component analysis and linear discriminant analysis were used to evaluate the proposed technique. The results demonstrated that the sensor array along with UV illumination could successfully discriminate the analytes at room temperature.‏
The Native Oyster Restoration Alliance (NORA) and the Berlin Oyster Recommendation: bringing back a key ecosystem engineer by developing and supporting best practice in Europe
Authors: Pogoda Bernadette , Brown Janet , Hancock Boze , Preston Joanne , Pouvreau Stephane , Kamermans Pauline , Sanderson William , von Nordheim Henning
Published: May 2019

Efforts to restore the native oyster Ostrea edulis and its associated habitats are gaining momentum across Europe. Several projects are currently running or being planned. To maximize the success of these, it is crucial to draw on existing knowledge and experience in order to design, plan and implement restoration activities in a sustainable and constructive approach. For the development of best practice recommendations and to promote multidimensional knowledge and technology exchange, the Native Oyster Restoration Alliance (NORA) was formed by partners from science, technology, nature conservation, consultancies, commercial producers and policy-makers. The NORA network will enhance scientific and practical progress in flat oyster restoration, such as in project planning and permitting, seed oyster production, disease management and monitoring. It also focuses on joint funding opportunities and the potential development of national and international regulatory frameworks. The main motivation behind NORA is to facilitate the restoration of native oyster habitat within its historic biogeographic range in the North Sea and other European seas along with the associated ecosystem services; services such as enhancing biodiversity, including enhanced fish stocks, nutrient cycling and sediment stabilization. NORA members agreed on a set of joint recommendations and strongly advise that any restoration measure should respect and apply these recommendations: The Berlin Oyster Recommendation is presented here. It will help guide the development of the field by developing and applying best practice accordingly. NORA also aims to combine the outreach activities of local projects for improved community support and awareness and to provide educational material to increase knowledge of the key ecological role of this species and increase awareness among regulators, permit providers and stakeholders. A synthesis of O. edulis restoration efforts in Europe is provided and underlines the general significance in the field.
Formation of conductive AlN buffer layer using spontaneous via-holes and realization of vertical AlGaN Schottky diode on a Si substrate
Authors: Kurose Noriko , Aoyagi Yoshinobu
Published: May 2019

A conductive AlN epitaxial layer is successfully realized by spontaneously forming via-holes filled with n-AlGaN inside an AlN buffer layer on a Si substrate. The via-holes are found to originate from the formation of an Al–Si alloy, produced from a small amount of Al supplied to the Si substrate at the initial stage of the crystal growth of the n-AlN buffer layer using metal organic chemical vapor deposition and successive selective growth of n-AlN on the Si surface. The via-holes are filled with conductive n-AlGaN by successive epitaxial growth of n-AlGaN, making the insulating n-AlN buffer layer conductive. The vertical conductivity through this n-AlN buffer layer is enhanced more than 540 times compared with an n-AlN buffer layer without via-holes. Using this conductive n-AlN buffer layer on the Si substrate, we successfully fabricated a vertical n-AlGaN Schottky diode on the Si substrate for the first time.
500 GHz plasmonic Mach-Zehnder modulator enabling sub-THz microwave photonics
Authors: Burla Maurizio , Hoessbacher Claudia , Heni Wolfgang , Haffner Christian , Fedoryshyn Yuriy , Werner Dominik , Watanabe Tatsuhiko , Massler Hermann , Elder Delwin L. , Dalton Larry R. , Leuthold Juerg
Published: May 2019

Broadband electro-optic intensity modulators are essential to convert electrical signals to the optical domain. The growing interest in terahertz wireless applications demands modulators with frequency responses to the sub-terahertz range, high power handling, and very low nonlinear distortions, simultaneously. However, a modulator with all those characteristics has not been demonstrated to date. Here, we experimentally demonstrate that plasmonic modulators do not trade-off any performance parameter, featuring—at the same time—a short length of tens of micrometers, record-high flat frequency response beyond 500 GHz, high power handling, and high linearity, and we use them to create a sub-terahertz radio-over-fiber analog optical link. These devices have the potential to become a new tool in the general field of microwave photonics, making the sub-terahertz range accessible to, e.g., 5G wireless communications, antenna remoting, Internet of Things, sensing, and more.
Temperature-selective emitter
Authors: Nishikawa Kazutaka , Yatsugi Kenichi , Kishida Yoshihiro , Ito Kota
Published: May 2019

To achieve control of radiative emissivity of a material, we propose and demonstrate a vanadium dioxide (VO2)-based temperature-selective emitter. This emitter comprises layered VO2 and thin W-doped VO2 with decreased metal-insulator transition temperature. Because a metal–insulator–metal structure is realized only in the temperature range 46–61 °C, the emissivity enhanced only in this temperature range. We analytically calculated the temperature-dependent emissivity spectra and experimentally measured the temperature-dependent reflectance spectra and emissivity. Direct heat flux measurements of the fabricated device showed emissivities of 0.19, 0.45, and 0.24 for temperatures of <30 °C, 46–61 °C, and >71 °C, respectively. The emitter presented in this study contributes to the realization of the active control of thermal emission in various situations.
Influence of LO and LA phonon processes on thermal-nonequilibrium excitation and deexcitation dynamics of excitons in GaN, AlN, and ZnO
Authors: Oki Kensuke , Ishitani Yoshihiro
Published: May 2019

The 1S-exciton density NX(1) in GaN, AlN, and ZnO is calculated for thermal-nonequilibrium states where the temperatures of an electron–hole system and phonons are different in the range of 10–400 K. The ratio of NX(1) in AlN to that in ZnO reaches 21 despite the similar exciton-binding energies of AlN and ZnO, which is due to the higher rate of excitation by LO-phonon absorption in ZnO. This result reveals that thermal-nonequilibrium states significantly affect the validity of evaluation methods for physical parameters such as internal quantum efficiency of radiation. The ratio of NX(1) in AlN to that in ZnO is enhanced from 2.2 to 18 by the occupation of states of the principal quantum number n from 2 to 5. This result demonstrates the importance of the discussion on the n≥3 states which have not been taken into account in other analyses. The main reason for the decrease in NX(1) is found to be the increase in the temperature of LO phonons rather than LA phonons, which indicates the importance of LO-phonon control in light-emitting devices. The results for general thermal-nonequilibrium states are nontrivial because the mechanisms of the population balance are complicated owing to the several-n occupation and the transition rates determined by various factors. Our analyses and discussions quantitatively unveil the LO- and LA-phonon effects on the thermal-nonequilibrium excitation and deexcitation dynamics of excitons and provide the basis for design of highly efficient light-emitting devices particularly in the ultraviolet region.
Dynamic modeling of carbon nanofiber growth in strong electric fields via plasma-enhanced chemical vapor deposition
Authors: Zhang Xuewei , Shneider Mikhail N.
Published: May 2019

Plasma enhanced chemical vapor deposition is an important method in the synthesis of carbon nanofibers which have been widely used in many technologies. Previous work devoted to the theoretical modeling of this process focused only on kinetics, i.e., the steady-state growth rate and its dependence on experimental conditions. This paper develops a dynamic model of a single carbon nanofiber grown in the cathode layer of a weakly ionized C2H2 glow discharge plasma. The model takes into account all main processes, including chemical kinetics, heat transfer, and the dynamics of electric field distribution. Specifically, the model considers the effects of a strong electric field on nanofiber growth: the field enhanced neutral particle flux and heat flux toward the catalyst and the increased catalyst temperature as a result of the thermal field emission current (along with its accompanying Nottingham effect). Numerical simulation shows that the increased fluxes caused by a strong electric field are unlikely to lead to a substantial acceleration of nanofiber growth. The growth tends to saturate, up to a complete stop, caused by the catalyst heating, which starts around the same time the field enhanced fluxes become significant. This serves as an alternate termination mechanism of nanofiber growth to the commonly-known catalyst poisoning. The competition and transition of the two mechanisms when changing the characteristic time of catalyst poisoning are shown. The results of this work help to improve the physical understanding of nanofiber growth and lay the foundation for further studies on other types of plasma-assisted nanofabrication.
A-site partially ordered La0.5Y0.5FeO3 and its multiferroic characteristics
Authors: Gao Ting Ting , Sun Tu Lai , Liu Xiao Qiang , Zhou Hai Yang , Tian He , Bellaiche Laurent , Chen Xiang Ming
Published: May 2019

The copresence of ferroelectricity and ferromagnetism inside the same compound is a rather scarce phenomenon, and therefore, the development of room-temperature multiferroic materials is a great challenge. In the present work, La0.5Y0.5FeO3 ceramics with La and Y ions partially ordered as a rocksalt type structure have been prepared. Such ordering leads to a polar P21nm phase, which is consistent with a particular type of hybrid improper ferroelectricity that has rarely been observed. Saturated polarization-electric field loops are determined at room-temperature with a remnant polarization of 0.11 μC/cm2, together with a room-temperature predominantly antiferromagnetic order accompanied by a weak magnetization, which renders our La0.5Y0.5FeO3 ceramics an example of a room-temperature multiferroic compound.
Structural origin for vibration-induced accelerated aging and rejuvenation in metallic glasses
Authors: Zhou Zhen-Ya , Peng Hai-Long , Yu Hai-Bin
Published: May 2019

Glassy materials are nonequilibrium and their energy states have crucial influences on properties. Recent studies have shown that oscillating deformations (vibrations) can cause either accelerated aging (lowering energy) or rejuvenation (elevating energy); however, the underlying atomic mechanisms remain elusive. Using metallic glasses (MGs) as model systems, we show that the vibration-induced accelerated aging is correlated with the strain field of the stringlike atomic motions stemming from the Johari-Goldstein (β) relaxation, whereas the rejuvenation is associated with nonlinear response and the formation of nanoscale shear bands attributing to the activation of α relaxation. Both processes are affected by thermal fluctuations, which result in an optimal temperature for accelerated aging. These results suggest intrinsic correlations among relaxation dynamics, mechanical properties, and the vibration induced structural rearrangements in MGs.
Analytic evaluation of first-order properties within the mean-field variant of spin-free exact two-component theory
Authors: Kirsch Till , Engel Franziska , Gauss Jürgen
Published: May 2019

We present a scheme for the calculation of energies and analytic energy gradients within spin-free exact two-component (SFX2C) theory in its mean-field variant, which we refer to as SFX2C-mf. In the presented scheme, the Foldy-Wouthuysen transformation is carried out after the spin-free four-component Hartree-Fock treatment such that in electron-correlated calculations only the non-mean-field part of the two-electron interactions is handled in an untransformed manner. The formulation of analytic gradients requires some adjustments in comparison with the nonrelativistic case, i.e., the additional solution of the spin-free Dirac Coulomb coupled-perturbed Hartee-Fock equations together with a simplified treatment of orbital relaxation at the SFX2C-mf level. The improved accuracy of SFX2C-mf in comparison with SFX2C-1e is demonstrated in the calculation of energies, dipole moments, and electric-field gradients for the hydrogen halides HX, X = F-At. It is shown that the main contribution to the improvement stems from the elimination of the error at the Hartree-Fock (HF) level; however, the corresponding correlation contribution is also improved such that SFX2C-mf can be considered a suitable scheme for the treatment of heavy-element compounds for which the error of SFX2C-1e is rather substantial.
Reducing adhesion energy of nano-electro-mechanical relay contacts by self-assembled Perfluoro (2,3-Dimethylbutan-2-ol) coating
Authors: Fathipour Sara , Almeida Sergio Fabian , Ye Zhixin Alice , Saha Bivas , Niroui Farnaz , King Liu Tsu-Jae , Wu Junqiao
Published: May 2019

To enable energy-efficient electronic devices for the future, nano-electro-mechanical (NEM) relays are promising due to their high ON/OFF current ratio and potential for low operating voltage. To minimize hysteresis and, consequently, relay operating voltage, it is imperative to reduce the relay contact adhesion, which can be achieved by coating the contacts with anti-stiction self-assembled monolayers. Herein we report a 71% reduction in hysteresis voltage by utilizing a branched perfluorocarbon antistiction molecule: Perfluoro (2,3-Dimethylbutan-2-ol) (PDB) on top of the tungsten contact surfaces. Experimental results show the operation of a PDB-coated NEM relay with abrupt switching, undetectably low OFF-state current, hysteresis voltage as low as 20 mV, and a large ON/OFF current ratio (>107).
Empirical scaling analysis of supersonic jet control using steady fluidic injection
Authors: Arun Kumar P. , Aravindh Kumar S. M. , Surya Mitra A. , Rathakrishnan E.
Published: May 2019

Following our previous work [Kumar et al., “Fluidic injectors for supersonic jet control,” Phys. Fluids 30(12), 126101 (2018)], we experimentally investigate the effect of fluidic injection on the mixing enhancement of a Mach 2.0 jet. The mass flow rate ratio Cm of the injectors to that of the main jet and the expansion ratio pe/pa (where pe and pa are the nozzle exit and atmospheric pressures, respectively) to understand the mixing capability at design and off-design conditions are examined in detail. Extensive Pitot pressure measurements are performed along the jet centerline, and the jet stream has been visualized using the shadowgraph technique in the orthogonal planes of the manipulated jet. The mixing capability of the manipulated jet quantified based on the reduction in supersonic core length ΔLc* exhibits a strong dependence on Cm and pe/pa. Empirical scaling analysis of the jet control reveals that the relationship ΔLc* = f1(Cm, pe, pa, D, d) may be reduced to ΔLc* = f2(ξ), where f1 and f2 are different functions and the scaling factor ξ = MRpe/pa(Dd)1.3, where MR is the momentum ratio of the injector to the main jet, D and d are the nozzle exit diameter and the injector exit diameter, respectively. The scaling parameter ΔLc* = f2(ξ) provides important insights into the jet control physics.
Enhancement of luminescence properties and stability in perovskite hybrid structure with CdSe/ZnS quantum dots
Authors: Cho Il-Wook , Ryu Mee-Yi
Published: May 2019

Semiconductor core-shell quantum dots (QDs) have been employed to enhance the optical properties and stability of perovskite (PS). The exciton behaviors in PS are influenced by its surface properties; therefore, the mechanisms of exciton recombination in this material should be studied in order to utilize PS-based optoelectronic devices effectively. We investigated the charge transfer from CdSe/ZnS core-shell QDs to organic–inorganic mixed halide PS using temperature-dependent photoluminescence (PL) and time-resolved PL spectroscopy. The PL intensity of the PS in the QD/PS hybrid structure increased to approximately 2.4 times that of the bare PS. In addition, the PL decay time of the PS in the QD/PS hybrid structure increased about 5.4 times (4.05 ns) compared to that (0.75 ns) in the bare PS, while the decay time of the QDs in the hybrid structure greatly reduced to 2.94 from 4.84 ns in the bare QDs. The enhancement of the PL intensity and decay time of the PS in the QD/PS hybrid structure are attributed to charge transfer from QDs and the decrease in defect states. A charge transfer efficiency of ∼39% was determined from QDs to the PS layer in the QD/PS hybrid structure at 300 K.
Retarded hydrodynamic interaction between two spheres immersed in a viscous incompressible fluid
Authors: Felderhof B. U.
Published: May 2019

Retarded or frequency-dependent hydrodynamic interactions are relevant for velocity relaxation of colloidal particles immersed in a fluid, sufficiently close that their flow patterns interfere. The interactions are also important for periodic motions, such as occur in swimming. Analytic expressions are derived for the set of scalar mobility functions of a pair of spheres. Mutual hydrodynamic interactions are evaluated in one-propagator approximation, characterized by a single Green function acting between the two spheres. Self-mobility functions are evaluated in a two-propagator approximation, characterized by a single reflection between the two spheres. The approximations should yield accurate results for intermediate and long distances between the spheres. Both translations and rotations are considered. For motions perpendicular to the line of centers, there is a translation-rotation coupling. Extensive use is made of Faxén theorems, which yield the hydrodynamic force and torque acting on a sphere in an incident oscillating flow. The derived results are important for the study of velocity relaxation of two interacting spheres immersed in a fluid and for the study of swimming of assemblies of spheres.
Proposed high-power beta cells from MgAlB14-type icosahedral-boron semiconductors
Authors: Emin David
Published: May 2019

Beta cells generate electric power as carrier-producing beta irradiation from incorporated radioisotopes bombard a series of p-n-junctions. However, radiation damage to the semiconductors commonly used in solar cells limits beta cells to extremely weak irradiations that generate concomitantly miniscule electric powers, e.g. micro-Watts. By contrast, beta cells that generate many orders-of-magnitude larger powers are possible with icosahedral boron-rich semiconductors since their bombardment-induced atomic displacements spontaneously self-heal. Furthermore, substitutions for Mg and Al atoms of icosahedral-boron-rich semiconductors based on the MgAlB14 structure can produce p-n junctions as electron transfers from doping-induced interstitial extra-icosahedral atoms convert some normally p-type materials to n-type. Moreover, electron-phonon interactions of the resulting readily displaceable interstitial cations with charge carriers foster their forming large polarons. Oppositely charged polarons repel one another at short range. These repulsions suppress the recombination of n-type with p-type polarons thereby increasing the beta-cell efficiency. All told, use of these icosahedral boron-rich semiconductors could enable beta cells with electric powers that are many orders of magnitude larger than those of existing beta cells. This development opens a new avenue for generating electricity from nuclear decays.