bluuebunny/crossref_metadata_2025 huggingface dataset:
Oral Pathobiont Activates Anti-Apoptotic Pathway, Promoting both Immune Suppression and Oncogenic Cell Proliferation
Authors: Arjunan Pachiappan , Meghil Mohamed M. , Pi Wenhu , Xu Jinxian , Lang Liwei , El-Awady Ahmed , Sullivan William , Rajendran Mythilypriya , Rabelo Mariana Sousa , Wang Tong , Tawfik Omnia K. , Kunde-Ramamoorthy Govindarajan , Singh Nagendra , Muthusamy Thangaraju , Susin Cristiano , Teng Yong , Arce Roger M. , Cutler Christopher W.
Published: November 2018

Chronic periodontitis (CP) is a microbial dysbiotic disease linked to increased risk of oral squamous cell carcinomas (OSCCs). To address the underlying mechanisms, mouse and human cell infection models and human biopsy samples were employed. We show that the ‘keystone’ pathogen Porphyromonas gingivalis, disrupts immune surveillance by generating myeloid-derived dendritic suppressor cells (MDDSCs) from monocytes. MDDSCs inhibit CTLs and induce FOXP3 + Tregs through an anti-apoptotic pathway. This pathway, involving pAKT1, pFOXO1, FOXP3, IDO1 and BIM, is activated in humans with CP and in mice orally infected with Mfa1 expressing P. gingivalis strains. Mechanistically, activation of this pathway, demonstrating FOXP3 as a direct FOXO1-target gene, was demonstrated by ChIP-assay in human CP gingiva. Expression of oncogenic but not tumor suppressor markers is consistent with tumor cell proliferation demonstrated in OSCC-P. gingivalis cocultures. Importantly, FimA + P. gingivalis strain MFI invades OSCCs, inducing inflammatory/angiogenic/oncogenic proteins stimulating OSCCs proliferation through CXCR4. Inhibition of CXCR4 abolished Pg-MFI-induced OSCCs proliferation and reduced expression of oncogenic proteins SDF-1/CXCR4, plus pAKT1-pFOXO1. Conclusively, P. gingivalis, through Mfa1 and FimA fimbriae, promotes immunosuppression and oncogenic cell proliferation, respectively, through a two-hit receptor-ligand process involving DC-SIGN+hi/CXCR4+hi, activating a pAKT+hipFOXO1+hiBIM−lowFOXP3+hi and IDO+hi- driven pathway, likely to impact the prognosis of oral cancers in patients with periodontitis.
Optimal positioning of storage systems in microgrids based on complex networks centrality measures
Authors: Korjani Saman , Facchini Angelo , Mureddu Mario , Caldarelli Guido , Damiano Alfonso
Published: November 2018

We propose a criterion based on complex networks centrality metrics to identify the optimal position of Energy Storage Systems in power networks. To this aim we study the relation between centrality metrics and voltage fluctuations in power grids in presence of high penetration of renewable energy sources and storage systems. For testing purposes we consider two prototypical IEEE networks and we compute the correlation between node centrality (namely Eigenvector, Closeness, Pagerank, Betweenness) and voltage fluctuations in presence of intermittent renewable energy generators and intermittent loads measured from domestic users. We show that the topological characteristics of the power networks are able to identify the optimal positioning of active and reactive power compensators (such as energy storage systems) used to reduce voltage fluctuations according to the common quality of service standards. Results show that, among the different metrics, eigenvector centrality shows a statistically significant exponential correlation with the reduction of voltage fluctuations. This finding confirms the technical know-how for which storage systems are heuristically positioned far from supply reactive nodes. This also represents an advantage both in terms of computational time, and in terms of planning of wide resilient networks, where a careful positioning of storage systems is needed, especially in a scenario of interconnected microgrids where intermittent distributed energy sources (such as wind or solar) are fully deployed.
The increasing variability of tropical cyclone lifetime maximum intensity
Authors: Song Jinjie , Klotzbach Philip J. , Tang Jianping , Wang Yuan
Published: November 2018

This study investigates long-term changes in the variability of TC intensity of global tropical cyclones, a topic which has been relatively infrequently studied to date. Our study finds that the variability of global TC lifetime maximum intensity (LMI), as measured by the LMI standard deviation, increases during 1981–2016. The increasing trend in LMI variability is statistically significant for both the Northern and Southern Hemispheres, with three individual TC basins: the western North Pacific, the South Indian and the South Pacific also having statistically significant increases. This increasing trend primarily results from distinct changes in the relative percentages of TCs with different intensities. When comparing two periods: 1981–1998 and 1999–2016, the proportions of weak and strong TCs increase, whereas moderate TCs occur relatively less frequently. This bimodal pattern of observed LMI distribution change is further linked to opposite trends in the average intensities of TCs that undergo rapid intensification (RI) during their lifetime (RI TCs) and those that do not (non-RI TCs). The LMI distributions of RI and non-RI TCs migrate to higher and lower intensities, respectively. Our results demonstrate from an observational perspective that strong TCs have strengthened while weak TCs have weakened as the global climate has warmed since 1981.
Structural and compositional study of precipitates in under-aged Cu-added Al-Mg-Si alloy
Authors: Maeda Takuya , Kaneko Kenji , Namba Takuya , Koshino Yuki , Sato Yukio , Teranishi Ryo , Aruga Yasuhiro
Published: November 2018

Atomic scale characterization of fine precipitates in an under-aged Cu added Al-Mg-Si alloy was carried out by combination of atomically-resolved annular dark-field scanning transmission electron microscopy and energy dispersive X-ray spectroscopy. Two types of precipitates were observed in the alloy. In the case of ordered β” precipitates, β” was proposed as Mg5-xAl2+xSi4 (x ≈ 1) with solute Cu atoms replacing Al site of β” precipitate. In the case of disordered precipitates, the precipitates were found to consist of β” sub-unit cells, three-fold symmetric structure without Cu atoms, Cu containing structures termed as “Cu sub-unit cluster”, and Q’ sub-unit cells. Among these structures, the morphologies of three-fold symmetric structure without Cu atoms, Cu sub-unit cluster, and Q’ sub-unit cell were almost the same, so that these structures should be the clusters of Q’ phase. Since the areal density, length and diameter of precipitates were almost equal between Cu free Al-Mg-Si alloy and Cu added Al-Mg-Si alloy, the increase of hardness by Cu addition should be due to the precipitation of Cu related precipitates, such as Cu sub-unit clusters and Q’ sub-unit cells.
Cardioprotective Effects of Curcumin-Nisin Based Poly Lactic Acid Nanoparticle on Myocardial Infarction in Guinea Pigs
Authors: Nabofa Williams E. E. , Alashe Oluwadamilola O. , Oyeyemi Oyetunde T. , Attah Alfred F. , Oyagbemi Ademola A. , Omobowale Temidayo O. , Adedapo Adeolu A. , Alada Akinola R. A.
Published: November 2018

Myocardial infarction (MI) is the most prevalent cause of cardiovascular death. A possible way of preventing MI maybe by dietary supplements. The present study was thus designed to ascertain the cardio-protective effect of a formulated curcumin and nisin based poly lactic acid nanoparticle (CurNisNp) on isoproterenol (ISO) induced MI in guinea pigs. Animals were pretreated for 7 days as follows; Groups A and B animals were given 0.5 mL/kg of normal saline, group C metoprolol (2 mg/kg), groups D and E CurNisNp 10 and 21 mg/kg respectively (n = 5). MI was induced on the 7thday in groups B-E animals. On the 9thday electrocardiogram (ECG) was recorded, blood samples and tissue biopsies were collected for analyses. Toxicity studies on CurNisNp were carried out. MI induction caused atrial fibrillation which was prevented by pretreatment of metoprolol or CurNisNp. MI induction was also associated with increased expressions of cardiac troponin I (CTnI) and kidney injury molecule-1 (KIM-1) which were significantly reduced in guinea pig’s pretreated with metoprolol or CurNisNp (P < 0.05). The LC50of CurNisNp was 3258.2 μg/mL. This study demonstrated that the formulated curcumin-nisin based nanoparticle confers a significant level of cardio-protection in the guinea pig and is nontoxic.
Transcriptomics in lung tissue upon respiratory syncytial virus infection reveals aging as important modulator of immune activation and matrix maintenance
Authors: Pennings Jeroen L. A. , Mariman Rob , Hodemaekers Hennie M. , Reemers Sylvia S. N. , Janssen Riny , Guichelaar Teun
Published: November 2018

Aging poses an increased risk of severe infection by respiratory syncytial virus (RSV). The many different biological pathways comprising the response to infection in lungs that are influenced by aging are complex and remain to be defined more thoroughly. Towards finding new directions in research on aging, we aimed to define biological pathways in the acute response to RSV that are affected in the lungs by aging. We therefore profiled the full transcriptome of lung tissue of mice prior to and during RSV infection both at young and old age. In the absence of RSV, we found aging to downregulate genes that are involved in constitution of the extracellular matrix. Moreover, uninfected old mice showed elevated expression of pathways that resemble injury, metabolic aberrations, and disorders mediated by functions of the immune system that were induced at young age only by an exogenous trigger like RSV. Furthermore, infection by RSV mounted stronger activation of anti-viral type-I interferon pathways at old age. Despite such exaggerated anti-viral responses, old mice showed reduced control of virus. Altogether, our findings emphasize important roles in aging-related susceptibility to respiratory disease for extracellular matrix dysfunctions and dysregulated immune activation in lungs.
Shape-control of super-branched Pd–Cu alloys with enhanced electrocatalytic performance for ethylene glycol oxidation
Authors: Hu Tianjun , Wang Ying , Xiao He , Chen Wenwen , Zhao Man , Jia Jianfeng
Published: November 2018

Pd–Cu alloys with adjustable morphologies were synthesized and examined as nanocatalysts for electro-oxidation of ethylene glycol.
A method to directly assay circRNA in real samples
Authors: Jiao Jin , Gao Tao , Shi Hai , Sheng Anzhi , Xiang Yang , Shu Yongqian , Li Genxi
Published: November 2018

‘MicroRNA sponge’ and duplex-specific nuclease (DSN)-assisted signal amplification were employed to propose a method for direct assay of circular RNA (circRNA) in real samples, which is rapid, sensitive, and easy to operate.
One dimensional hierarchical BiOCl microrods: their synthesis and their photocatalytic performance
Authors: Peng Yin , Mao Yan Ge , Kan Peng Fei
Published: November 2018

One dimensional hierarchical BiOCl microrods are controlled synthesized via hydrothermal method using sodium citrate as structure-agent. These hierarchical BiOCl architectures exhibit outstanding photocatalytic activity for degrading organic dyes and phenol.
Structure determination of fatty acid ester biofuelsvia in situcryocrystallisation and single crystal X-ray diffraction
Authors: Prathapa Siriyara Jagannatha , Slabbert Cara , Fernandes Manuel A. , Lemmerer Andreas
Published: November 2018

In situcryocrystallisation enabled the crystal structure determination of a homologous series of low-meltingn-alkyl methyl esters Cn−1H2n+1CO2CH3.
Assessment of DFT for endohedral complexes' dipole moment: PNO-LCCSD-F12 as a reference method
Authors: Kozłowska Justyna , Schwilk Max , Roztoczyńska Agnieszka , Bartkowiak Wojciech
Published: November 2018

We present a systematic evaluation of the performance of a wide range of exchange–correlation functionals and related dispersion correction schemes for the computation of dipole moments of endohedral complexes, formed through the encapsulation of an AB molecule (AB = LiF, HCl) inside carbon nanotubes (CNTs) of different diameter.
Application of (4+3) cycloaddition strategies in the synthesis of natural products
Authors: Yin Zengsheng , He Yun , Chiu Pauline
Published: November 2018

This review summarizes the applications of (4+3) cycloadditions, both classical and formal, in the syntheses of natural products in the last two decades.
KLTL–MCM-41 micro–mesoporous composite as a solid base for the hydrogenation of sugars
Authors: Tangale Nilesh P. , Niphadkar Prashant S. , Joshi Praphulla N. , Dhepe Paresh L.
Published: November 2018

An approach to the synthesis of KLTL–MCM-41 micro–mesoporous composites of varying SiO2/Al2O3 molar ratio (20–8) was designed by following green technology.
Phosphomolybdic acid as an efficient hole injection material in perovskite optoelectronic devices
Authors: Fallah Hamidabadi Vahid , Momblona Cristina , Pérez-Del-Rey Daniel , Bahari Ali , Sessolo Michele , Bolink Henk J.
Published: November 2018

Phosphomolybdic acid (PMA) is a solution-processable high work function material which can be used as hole-injection interface in perovskite solar cells and LEDs.
Inducing the distinctly different fluorescence properties of a tetraphenylethene (TPE) derivative modified lanthanide nanowire upon the addition of a pair ofcis- andtrans-isomers of fatty acids
Authors: Wu Jianbin , Huang Songyang , Gao Yan , Li Jiale , Wang Xi
Published: November 2018

Different fluorescence properties of a tetraphenylethene (TPE) derivative modified lanthanide nanowire were induced by a pair ofcis- andtrans-isomers of fatty acids.
Process-induced cell wall permeability modulates the in vitro starch digestion kinetics of common bean cotyledon cells
Authors: Pallares Pallares Andrea , Alvarez Miranda Beatriz , Truong Ngoc Quynh Anh , Kyomugasho Clare , Chigwedere Claire Maria , Hendrickx Marc , Grauwet Tara
Published: November 2018

Cell wall barrier role during in vitro simulated digestion of starch in common bean cotyledon cells can be modified through variation of thermal processing intensity.
Genistein and daidzein decrease food intake and body weight gain in mice, and alter LXR signalingin vivoandin vitro
Authors: Luo Ting , Miranda-Garcia Omar , Sasaki Geoff , Wang Jinling , Shay Neil F.
Published: November 2018

Genistein and daidzein decrease mice food intake, ameliorate symptoms of metabolic syndrome, including decreasing body weight gain, and improving glucose metabolism, and appear to produce differential effects, possiblyviathe regulation of LXR-mediated pathways.
Recent advances in the Suzuki–Miyaura cross-coupling reaction using efficient catalysts in eco-friendly media
Authors: Hooshmand Seyyed Emad , Heidari Bahareh , Sedghi Roya , Varma Rajender S.
Published: November 2018

The ever-increasing interest in the Suzuki–Miyaura cross-coupling reaction (SMR) and its applications, with more than 40 years of history, has increased exponentially in the last decade, which speaks volumes about its efficiency and effectiveness; recent improvements in terms of efficient catalysts in benign media are highlighted.
Microfluidic communicating vessel chip for expedited and automated immunomagnetic assays
Authors: Yang Yang , Zeng Yong
Published: November 2018

A simple device exploits hydrostatic pressure-driven flow to simplify and expedite the immunoassay workflow.
Antifouling behavior of self-renewal acrylate boron polymers with pyridine-diphenylborane side chains
Authors: Li Yakun , Chen Rongrong , Feng YanHua , Liu Lianhe , Sun Xun , Tang Liang , Takahashi Kazunobu , Wang Jun
Published: November 2018

The environmentally friendly polymers showed excellent antifouling performances in raft tests by the hydrolysis of diphenyl borane pyridine side groups.
Detection of lymph node metastasis with near-infrared upconversion luminescent nanoprobes
Authors: Qiu Shanshan , Zeng Jianfeng , Hou Yi , Chen Lei , Ge Jianxian , Wen Ling , Liu Chunyan , Zhang Youjiu , Zhu Ran , Gao Mingyuan
Published: November 2018

Near-infrared upconversion luminescent nanoprobes with outstanding tissue penetration depth and excellent tumor targeting ability realized the detection of lymph node metastasis.
Templated direct growth of ultra-thin double-walled carbon nanotubes
Authors: Shi Lei , Wei Jinquan , Yanagi Kazuhiro , Saito Takeshi , Cao Kecheng , Kaiser Ute , Ayala Paola , Pichler Thomas
Published: November 2018

Double-walled carbon nanotubes (DWCNTs) combined the advantages of multi-walled (MW-) and single-walled (SW-) CNTs can be obtained by transforming different kinds of SWCNTs as templates by high-temperature annealing without additional carbon source as a universal route.
Inverse-electron-demand Diels–Alder reactions of α,β-unsaturated hydrazones with 3-methoxycarbonyl α-pyrones
Authors: Hashimoto Yoshimitsu , Abe Ryo , Morita Nobuyoshi , Tamura Osamu
Published: November 2018

Inverse-electron-demand Diels–Alder reactions of 3-electron-withdrawing group substituted α-pyrones with α,β-unsaturated hydrazones as electron-rich counterparts are catalyzed by Eu(hfc)3 to afford bicyclic lactone cycloadducts.
Tunable bandwidth of double electromagnetic induced transparency windows in terahertz graphene metamaterial
Authors: Wang Yue , Tao Mengning , Pei Zhen , Yu Xuzheng , Wang Benhua , Jiang Jiuxing , He Xunjun
Published: November 2018

By patterning graphene on a SiO2/Si substrate, in this paper, we design and numerically investigate double electromagnetic induced transparency (EIT) windows in a terahertz metamaterial based on a π-like graphene structure.
Biocompatible zwitterionic copolymer-stabilized magnetite nanoparticles: a simple one-pot synthesis, antifouling properties and biomagnetic separation
Authors: Boonjamnian Supannika , Trakulsujaritchok Thanida , Srisook Klaokwan , Hoven Voravee P. , Nongkhai Piyaporn Na
Published: November 2018

A simple one-pot synthesis of biocompatible and antifouling magnetite nanoparticles (Fe3O4NPs) was developed.
Green synthesis of bio-molecule encapsulated magnetic silver nanoparticles and their antibacterial activity
Authors: Ullah A. K. M. Atique , Kabir M. F. , Akter M. , Tamanna A. N. , Hossain A. , Tareq A. R. M. , Khan M. N. I. , Kibria A. K. M. Fazle , Kurasaki Masaaki , Rahman M. M.
Published: November 2018

Persuaded by the necessity of finding new sources of antibiotics, Ag NPs were synthesized by adopting a newly developed green synthesis technique and subsequently, their antibacterial activity against different pathogenic bacteria was evaluated.
Controlled size reduction of rare earth doped nanoparticles for optical quantum technologies
Authors: Liu Shuping , Serrano Diana , Fossati Alexandre , Tallaire Alexandre , Ferrier Alban , Goldner Philippe
Published: November 2018

Chemical etching is a promising way to synthesize RE:Y2O3 nanoparticles with controlled size and long coherence lifetimes, opening the way to optical micro/nano-cavities coupling and efficient nanoscale quantum memories and processors.
CuInS2–In2Se3 quantum dots – a novel material via a green synthesis approach
Authors: Simi N. J. , Kuriakose Libin , Vinayakan R. , Ison V. V.
Published: November 2018

Novel CuInS2–In2Se3 QDs prepared by a two stage organometallic colloidal synthesis.
An efficient nickel/silver co-catalyzed remote C–H amination of 8-aminoquinolines with azodicarboxylates at room temperature
Authors: Zhao Ruinan , Yang Yaocheng , Wang Xia , Ren Peng , Zhang Qian , Li Dong
Published: November 2018

C–H amination at the C5 position of 8-aminoquinolines with azodicarboxylates proceeded efficiently using a nickel/silver co-catalyst at room temperature without any additional ligand, base or oxidant.
Arbuscular mycorrhizal inoculation increases molybdenum accumulation but decreases molybdenum toxicity in maize plants grown in polluted soil
Authors: Shi Zhaoyong , Zhang Jiacheng , Wang Fayuan , Li Ke , Yuan Weikang , Liu Jianbo
Published: November 2018

Arbuscular mycorrhizal inoculation increases Mo accumulation but decreases Mo phytotoxicity in maize plants grown in polluted soil.
Exploring the binding pattern between pepsin and deferasirox using detailed experimental and computer simulation methods
Authors: Yang Ji , Du Qiaohong , Gan Na , Chen Yongkuan , Yang Liu , Liu Zhihua , Zhao Hui , Sun Qiaomei , Li Hui
Published: November 2018

Investigation on the binding properties of deferasirox to pepsin.
Development of high-utilization honeycomb-like α-Ni(OH)2 for asymmetric supercapacitors with excellent capacitance
Authors: Zhou Shaojie , Cui Shizhong , Wei Wutao , Chen Weihua , Mi Liwei
Published: November 2018

The low utilization rate of active materials has been a critical obstacle for the industrialization of ultracapacitors.
Electrospun cellulose acetate doped with astaxanthin derivatives fromHaematococcus pluvialisforin vivoanti-aging activity
Authors: Nootem Jukkrit , Chalorak Pawanrat , Meemon Krai , Mingvanish Withawat , Pratumyot Kornkanya , Ruckthong Leela , Srisuwannaket Choladda , Niamnont Nakorn
Published: November 2018

The astaxanthin derivatives loaded CA fibers enhanced the percentage survival ofC. elegansupto 56.17% after adding paraquat and it stability increased with 1.7 times by using DPPH scavenging assay.
Asymmetric maltose neopentyl glycol amphiphiles for a membrane protein study: effect of detergent asymmetricity on protein stability
Authors: Bae Hyoung Eun , Du Yang , Hariharan Parameswaran , Mortensen Jonas S. , Kumar Kaavya K. , Ha Betty , Das Manabendra , Lee Hyun Sung , Loland Claus J. , Guan Lan , Kobilka Brian K. , Chae Pil Seok
Published: November 2018

An asymmetric MNG, MNG-8,12, provided enhanced stability to human G protein-coupled receptors (GPCRs) compared to the symmetric MNG, MNG-3.
Nucleotide and structural label identification in single RNA molecules with quantum tunneling spectroscopy
Authors: Abel Gary R. , Korshoj Lee E. , Otoupal Peter B. , Khan Sajida , Chatterjee Anushree , Nagpal Prashant
Published: November 2018

We describe a nanoelectronic method for identifying single ribonucleotides and structural modifications, laying groundwork for single-molecule RNA sequencing/structural mapping.
Rare “Janus”-faced single-molecule magnet exhibiting intramolecular ferromagnetic interactions
Authors: Alexandropoulos Dimitris I. , Vignesh Kuduva R. , Stamatatos Theocharis C. , Dunbar Kim R.
Published: November 2018

The unusual ferromagnetically coupled compound was prepared by the use of Me3SiN3 with the metal ions being exclusively bridged by end-on N3−. Th cationic molecule is a rare example of a 3d-metal cluster exhibiting a “Janus”-faced SMM behavior for the dried and wet forms.
Drop mobility on superhydrophobic microstructured surfaces with wettability contrasts
Authors: Kita Yutaku , Mackenzie Dover Coinneach , Askounis Alexandros , Takata Yasuyuki , Sefiane Khellil
Published: November 2018

Influence of wettability contrasts and contact angle hysteresis on drop velocity and surface energy analysis describing the drop motion.
The roles of oxygen vacancies, electrolyte composition, lattice structure, and doping density on the electrochemical reactivity of Magnéli phase TiO2anodes
Authors: Jing Yin , Almassi Soroush , Mehraeen Shafigh , LeSuer Robert J. , Chaplin Brian P.
Published: November 2018

Surface deactivation and reactivation processes on the Magnéli phase electrode surface in H2SO4electrolyte.
TiO2 nanocrystals embedded in sulfur-doped porous carbon as high-performance and long-lasting anode materials for sodium-ion batteries
Authors: Li Junfeng , Zhang Xiaojie , Han Lu , Yan Dong , Hou Shujin , Lu Ting , Yao Yefeng , Pan Likun
Published: November 2018

TiO2 nanocrystals embedded in sulfur-doped porous carbon, synthesized through a solvothermal reaction and pyrolysis with sulfur powder, exhibit excellent performance for sodium-ion batteries.
One-pot formic acid dehydrogenation and synthesis of benzene-fused heterocycles over reusable AgPd/WO2.72 nanocatalyst
Authors: Yu Chao , Guo Xuefeng , Shen Bo , Xi Zheng , Li Qing , Yin Zhouyang , Liu Hu , Muzzio Michelle , Shen Mengqi , Li Junrui , Seto Christopher T. , Sun Shouheng
Published: November 2018

Nanocatalyst with AgPd nanoparticles coupled to WO2.72 nanorods combines multi-step reactions in one-pot to prepare complex heterocycles under mild conditions.
Bandwidth‐tunable filtering balun based on compact 3D configuration
Authors: Yao Lidan , Wu Yongle , Li Mingxing , Wang Weimin , Liu Yuanan
Published: November 2018

For the first time, a novel bandwidth‐tunable filtering balun based on compact 3D configuration is presented. The overall design is basically composed of a two‐layer horizontal feeding plane, a three‐layer vertically mounted plane, and the transmission‐line circuits disposed on both. Implementing the ring resonator in vertical double‐sided parallel‐strip line, the complete horizontal ground and frequency‐independent phase difference are subtly combined. Connecting the shunt varactor diodes with the inserted vertical ground, the desirable filtering property and flexible bandwidth tunability are splendidly fulfilled. A prototype balun centred at 1.53 GHz is fabricated. The measured operating bandwidth is dynamically tuned from 0.87 to 1.23 GHz with a return loss <−10 dB, forcefully validating the design concept.
Stability of switched positive linear time‐delay systems
Authors: Liu Li‐Juan , Zhao Xudong , Wu Di
Published: November 2018

In this study, the authors analyse the stability of switched positive linear time‐delay systems. By developing a novel multiple discontinuous co‐positive Lyapunov–Krasovskii functional approach, the stability conditions are established for switched positive time delay systems by a linear programming approach under mode‐dependent average dwell time switching. Moreover, under average dwell time switching, the corresponding stability conditions are also proposed. It is shown that their results can obtain smaller lower bounds on dwell time. Finally, simulation results are given to show the effectiveness of their methods.
Reduce–factor–solve for fast Thevenin impedance computation and network reduction
Authors: Sommer Stefan , Aabrandt Andreas , Jóhannsson Hjörtur
Published: November 2018

The complexity and volatility of power system operation increase when larger parts of the power production is based on distributed and non‐controllable renewable energy sources. Ensuring stable and secure operation becomes more difficult in these modern power systems. For security assessment, the results of traditional offline simulations may become obsolete prior to the completion of the assessment. In contrast, real‐time stability and security assessment aims at online computation, and it is therefore dependent on very fast computation of properties of the grid operating state. The study develops the reduce–factor–solve approach to real‐time computation of two key components in real‐time assessment methods, network reduction, and calculation of Thevenin impedances. The aim is to allow online stability assessment for very complex networks. The theoretical foundation behind the reduce–factor–solve approach is described together with the ability to handle both algorithms in a common framework. By exploiting parallelisation of the reduce and solve steps in combination with fast matrix factorisation, Thevenin impedances and reduced networks are computed much faster than previous approaches. The reduce–factor–solve algorithm is evaluated on power grids of varying complexity to show that Thevenin impedance computation and network reduction for complex power systems can be performed on a milliseconds time scale.
Improved power flow control strategy of the hybrid AC/DC microgrid based on VSM
Authors: Liu Ziwen , Miao Shihong , Fan Zhihua , Liu Junyao , Tu Qingyu
Published: November 2018

The hybrid AC/DC microgrid with different types of distributed generations (DGs) and load demands is considered to be the preferred microgrid mode in the future. For hybrid AC/DC microgrid, autonomous and bidirectional power flow between AC and DC subgrids with superior dynamic performance is the fundamental objective to realise proportional power sharing and robust operation. In this study, an improved active power control strategy of the bidirectional AC/DC main converter (BMC) based on virtual synchronisation machine (VSM) for inertia improvement of the AC bus frequency and DC bus voltage of the hybrid microgrid is proposed. The VSM control is derived through the virtual inertia equation and the virtual capacitance equation, which can manage the AC frequency and DC voltage simultaneously. Then, the small signal and large signal characteristics analysis of the BMC are conducted to analyse the VSM control feature with different control parameters. On the basis of the small signal analysis, a proportional power sharing principle to select the control parameters is given to make DGs share the power commensurate with their power ratings. Finally, simulation cases are carried out to show the validity and efficiency of the proposed control strategy.
Tri‐level transmission Expansion planning under intentional attacks: virtual attacker approach‐part II: case studies
Authors: Nemati Hadi , Latify Mohammad Amin , Yousefi Gholam Reza
Published: November 2018

In the second part of this two‐part study, the authors numerically validate and analyse the tri‐level transmission expansion planning (TTEP) which is formulated and explained in the first part. TTEP is performed aim to minimise the destructive impacts of physical intentional attacks. At first, an illustrative example (a three‐bus system) is provided to show the capability of the proposed TTEP model to find the Nash equilibria and identify the Pareto equilibria of the game among virtual attackers. Then, the proposed TTEP model is applied on the Garver network and the modified IEEE 30‐bus network and numerical results for several case studies are provided. The numerical results confirm the proposed model and show its significant capability in reducing the vulnerability of the power networks.
Ladder network parameters identification of an isolated winding by combining the intelligent optimisation algorithm and GNIA
Authors: Ren Fuqiang , Xiao Yao , Zhan Cao , Liu Yong , Yang Fan , Ji Shengchang , Zhu Lingyu
Published: November 2018

The ladder network parameter identification for transformer winding is crucial for the interpretation of the frequency response function data. The traditional identification method, mainly based on intelligent optimisation algorithm, is generally very time‐consuming due to a large amount of computation. This study proposes to combine the intelligent algorithm and Gauss–Newton iteration algorithm (GNIA) to improve the optimisation efficiency notably with a sharply dropped calculation workload. These two methods are well‐complementary since the intelligent algorithm holds excellent global search ability while the search of the GNIA is directional and quantitative. This study solves three key problems for the combined algorithms. The first problem is the calculation of the least‐square correction solution to the network parameters in the iteration algorithm. The treatment of the ill‐conditioned Jacobian matrix in the iteration algorithm is the second challenge. Another issue is the determination of the network parameter with zero sensitivity. The identification results on an isolated winding show that the combined algorithms can obtain a more precise solution with far less amount of computation.
Short-term variability and mass loss in Be stars
Authors: Baade D. , Pigulski A. , Rivinius Th. , Wang L. , Martayan Ch. , Handler G. , Panoglou D. , Carciofi A. C. , Kuschnig R. , Mehner A. , Moffat A. F. J. , Pablo H. , Rucinski S. M. , Wade G. A. , Weiss W. W. , Zwintz K.
Published: November 2018

Context. In early-type Be stars, groups of nonradial pulsation (NRP) modes with numerically related frequencies may be instrumental for the release of excess angular momentum through mass-ejection events. Difference and sum/harmonic frequencies often form additional groups.

Aims. The purpose of this study is to find out whether a similar frequency pattern occurs in the cooler third-magnitude B7-8 IIIe shell starνPup.

Methods. Time-series analyses were performed of space photometry with BRITE-Constellation (2015, 2016/17, and 2017/18), SMEI (2003–2011), and HIPPARCOS(1989–1993). Two IUE SWP and 27 optical echelle spectra spanning 20 years were retrieved from various archives.

Results. The optical spectra exhibit no anomalies or well-defined variabilities. A magnetic field was not detected. All three photometry satellites recorded variability near 0.656 c/d which is resolved into three features separated by ∼0.0021 c/d. Their first harmonics and two combination frequencies form a second group, whose features are similarly spaced by 0.0021 c/d. The frequency spacing is very nearly but not exactly equidistant. Variability near 0.0021 c/d was not detected. The long-term frequency stability could be used to derive meaningful constraints on the properties of a putative companion star. The IUE spectra do not reveal the presence of a hot subluminous secondary.

Conclusions.νPup is another Be star exhibiting an NRP variability pattern with long-term constancy and underlining the importance of combination frequencies and frequency groups. This star is a good target for efforts to identify an effectively single Be star.
Prediction of the Temperature Distribution During Friction Stir Welding (Fsw) With A Complex Curved Welding Seam: Application In The Automotive Industry
Authors: Meyghani Bahman , Awang Mokhtar B
Published: November 2018

Advanced welding of complex geometries promises significant development in the automotive industry. Friction Stir Welding (FSW) as a solid-state welding technique has spread quickly since its initial development by TWI in 1991. It has found applications in various industries, including railway, automotive, maritime and aerospace. Temperature during FSW plays a significant role, therefore thermal analysis of the process provides the opportunity to understand the process in detail, and also allows one to save energy and cost as well. However, experimental investigation of the thermal behaviour is challenging, because of inaccuracy in the measuring instruments. Thus, Finite Element Methods (FEMs) offer an appropriate approach for thermal modelling of the process. There is also a dilemma in defining the perpendicular movement of the tool on a curved surface. To clarify the problem, the tool needs to follow a regular pattern during curved movement, and it should have a perpendicular position to the surface at each point. However, previous literature modelled only a single point movement for the tool. Thus, the finite element package needs to be modified to develop a precise perpendicular movement for the tool. In this paper, a VDISP user defined subroutine is used to modify Abaqus® software for thermal analysis of a complex curved plate. The results of the paper show that the problem of the perpendicular movement of the tool is resolved and the thermal behaviour of the FSW is done with remarkable accuracy.
Soot Blowing Operation Optimization Using PSO Method by Studying Behaviour of Operating Parameter in Sub Critical Coal Fired Power Plant
Authors: Sundaram Taneshwaren , Ismail Firas Basim , Gurusingam Pogganeswaren
Published: November 2018

Coal, natural gas and fuel-oil are three major fossil fuels sources are vastly used in electrical power generation sector in Malaysia. In a coal fired power plant, the major byproducts resulting from coal combustion inside boiler is soot, ash and NOx emissions. Boiler fouling and slagging are common problems that leads reduces heat transfer rate in furnace and boiler efficiency. This happens when soot and ash is formed and deposited along the boiler tubes, furnaces and heaters. Hence, soot blowing operation is used to blow off steam in affected areas of boilers as a cleaning mechanism. However, current soot blowing operation is practiced through operator’s visual inspection of slagging or fouling rate in furnace. This leads to inefficient soot blowing operation that effects the plant’s operating and maintenance cost. Thus, by studying behavior of operating parameters, soot blowing operation can be optimized to reduce unnecessary soot blowing operation in power plant.
Design of Distributed Control and Emergency Shutdown System for Urea and Ammonia Plant
Authors: Borikar Radha Ravindra , Monica Subashini M.
Published: November 2018

In modern process industries, the need for automation has become necessary to improve the feasibility of production. Automation reduces the possibility of human error and also ensures accuracy of output. In automation and process industries, DCS is used to control several processes being carried out simultaneously with minimum scope for failure. In this project, we have proposed a design on Distributed Control System and Emergency Shutdown System which controls the processing of urea and ammonia. The software used for the Distributed Control System is Centum VP (Vigilant Plant) and the logic designer tool is used to design the control logics of the DCS and ESD.
Design a New Receiver for the Central Tower of Solar Energy
Authors: Khlief Ayad K. , Gilani Syed I.U. , Al-Kayiem Hussain H. , Mohammad Sanan T.
Published: November 2018

Heat loss is an important factor in the performance of the solar receiver for concentrated solar systems (CSP). This study presents a proposed model for a new design for the receiver using an evacuated tube that has been performed to reduce convection loss and radiative heat losses with a zigzag distribution to minimize spillage losses. In this study, simulation results showed that the energy input increases with increased solar irradiation; the increase ranges from 3429 to 5584 W and 1879 to 3875 W at 9 AM and 13 PM for preheater and superheater respectively. The thermal efficiency of the receiver was around 72%.
Experiment and Numerical Studies on Heat Loss in a Hydro-Distillation with Various Insulations
Authors: Abdullah Mohd Haslizam , Ghani Saiful Anwar Che , Mohamed Siti Rohaida
Published: November 2018

In Asia, Agarwood oil is obtained by conventional extraction methods which consume significant energy, amount of solvents, and process time. One of the conventional extraction methods is traditional hydrodistillation using stainless steel distiller covered by concrete. This study evaluates the heat loss during agarwood during agarwood hydro-distillation process with the aim at optimizing it using insulation techniques. Six insulation materials namely, Polyurethane, Aluminum Silicate, Glass Wool, Mineral Wool and Nitrile Rubber have been investigated experimentally and numerically using software Engineering Equation Solver (EES) to determine their effectiveness in reducing the heat loss from the boiler. Interestingly, higher heat loss recorded by the boiler surrounded by the concrete than when the boiler was heated barely. The best insulations with more than 18% efficiency of bare distiller demonstrated by glass wool and polyurethane whilst the worst efficiency was Aluminum Silicate. This finding is significant to help designers to choose the insulation material for improving engineering economics of hydro-distillation process.
Construct Coil Probe Using GMR Sensor for Eddy Current Testing
Authors: Faraj Moneer A , Abdalla Ahmed N , Samsuri Fahmi Bin , Rifai Damhuji , Ali Kharudin
Published: November 2018

Eddy current testing is a widely applied non-destructive technique in different sections of industries. Nowadays eddy current testing is an accurate, widely used and well-understood inspection technique, particularly in the aircraft and nuclear industries. The main purpose of this paper is to construct an eddy current probe by using transmission coil and using a Giant Magneto resistance (GMR) sensor for detection medium. This probe only use a magnetic field to operational in detection of flaws. A transmission coil is an object made from a material that is magnetized and creates its own persistent magnetic field. A GMR-coil probe has been used to inspect two different material of calibration block. Experimental results obtained by scanning A GMR-coil probe over Brass calibration block has 10 slots with different depth from 0.5mm to 5mm and mild steel has 8 slots with different depth from 0.5mm to 4mm are presented. The result prove that GMR-coil probe that operated using a magnetic field and sensor more effective on ferromagnetic material.
Parametric Optimization of the Poly (Nvinylcaprolactam) (PNVCL) Thermoresponsive Polymers Synthesis by the Response Surface Methodology and Radial Basis Function neural network
Authors: Mohammed Marwah N. , Yusoh Kamal Bin , Shariffuddin Jun Haslinda Binti Haji
Published: November 2018

A novel comparison study based on a radial basis function neural network (RBFNN) and Response Surface Methodology (RSM) is proposed to predict the conversion rate (yield) of the experimental data for PNVCL polymerization. A statistical and optimization model was performing to show the effect of each parameter and their interactions on the conversion rate. The influence of the time, polymerization temperature, initiator concentration and concentration of the monomer were studied. The results obtained in this study indicate that the RBFNN was an effective method for predicting the conversion rate. The time of the PNVCL polymerization as well as the concentration of the monomer show the maximum effect on the conversion rate. In addition, compared with the RSM method, the RBFNN showed better conversion rate comparing with the experimental data.
Study of Impact Erosion of Oil and Gas Flowlines with Micro-sized Sand Particles
Authors: Naz Muhammad Y , Sulaiman Shaharin A , Ismail Noor I , Inayat Muddasser , Shukrullah Shazia , Ghaffar Abdul
Published: November 2018

The oil and gas produced from the reservoirs of relatively low formation strength inevitably carry micro-sized sand particles, which adversely influence the flow-lines and other installations. The financial deliberations favor the choice of low-cost metals, in general, carbon steel as a flow-line material. Yet, there are many cases where carbon steel been substituted with a low-cost stainless steel. The corrosion resistance of the stainless-steel is well accepted. However, there is another type of deformation that is not well studied and understood is its erosion resistance. The objective of this study is to investigate the factors affecting the erosion of stainless steel placed in a dry sand stream of micro-size particles. The manipulated variables were sand size, impingement angle, gas flow velocity, and nozzle distance. The obtained results showed that the large particle size, high fluid-flow velocity and short nozzle distance would result in more severe erosion of the stainless-steel coupons.
Carbon-13 Characterization and Modelling for Temperature Measurement-Based Proton Frequency
Authors: Abdullah Monis Abdulmanan , Albarody Thar M. Badri , Yusoff Puteri Sri M. Bt Megat , Hussein Alaa Raad
Published: November 2018

The physical substance at high energy level with specific circumstances; tend to behave harsh and complicated, meanwhile, sustaining equilibrium or non-equilibrium thermodynamic of the system. Measurement of the temperature by ordinary techniques in these cases is not applicable at all. Likewise, there is a need to apply mathematical models in numerous critical applications to measure the temperature accurately at an atomic level of the matter. Those mathematical models follow statistical rules with different distribution approaches of quantities energy of the system. However, these approaches have functional effects at microscopic and macroscopic levels of that system. Therefore, this research study represents an innovative of a wireless temperature sensor, which utilizes proton resonance frequency of carbon-13 isotope material. In addition to that, this study also addresses the energy distribution of the particles by selecting an updated appropriate approach that has interesting points of limitation in the number of degree of freedom: (1) thermodynamically limits and (2) theoretical statistical thermodynamics observations. Lastly, the main idea of this paper is to visualize the analysis of temperate in the nanoscale system via statistical thermodynamics approach along with the material characterization of carbon-13 isotope.
Rheumatic Heart Disease Classification Using Adaptive Filters
Authors: Panda Nanda Kishor , Monica Subashini M. , Kejriwal Milind
Published: November 2018

An efficient and innovative method has been proposed in this paper to detect heart murmurs as a method to identify rheumatic fever with the use of adaptive filters, transform techniques and Neural Network Algorithms by considering various parameters such as number of peaks, Signal to Noise Ratio (SNR) and Power Spectral Density. Under optimum conditions the classification returned exact outputs even when the neural network was trained under false positive data thus showing its effectiveness.
Energy Content Of The Domestic Wastewater Sludge Dried In The Thermal Dryer
Authors: Zakaria M.S. , Hassan Suhaimi , Faizairi M.N.
Published: November 2018

Domestic Wastewater Sludge (DWS) is considered as one of the largest contributor waste in Malaysia. Converting this waste as an alternative fuel can eliminate the disposal problem and reduce the environmental issue that causes by this waste. However, the initial moisture content in DWS is around 90% and in order to convert this waste into useful solid fuel, the moisture content of this waste must be reduced to 20% and below. Thermal dryer is one of the efficient dryer for the DWS that is capable of drying the huge volume of DWS in a short period of time. This study focused on the energy usage by the thermal dryer with several operating condition and the effect to the Higher Heating Value (HHV) of DWS. Based on the study, the higher heating value of DWS obtained from the experimental of thermal dryer found to be comparable with the results obtained from other biomass types which is around 9-15.86 MJ/kg. After analysis and comparison of the energy from the dried DWS and energy consumed by the dryer, the best operating condition of the thermal dryer was at 275 kW of power rating with speed of 30 and 10 rpm (revolution per minute) of the screw conveyor in the feeder and dryer respectively.
Thermal Diffusion Performance of a Diffuser by various Guide Vanes configurations
Authors: Chikere Aja O. , Al-Kayiem Hussain H. , Karim Zainal Ambri A.
Published: November 2018

The use of vane-less diffuser with large diffusion angle has shown a setback in the diffusion process of high temperature working fluids. The hot gas flow was characterized as a jet-like flow. This paper presents problem, encountered practically, using a vane-less diffuser with large diffusion angle and how the problem is solved by CFD simulation. The investigated thermal diffuser has a length of 0.3 m, an inlet to outlet crosssectional area ratio of 1:25 and diffusion angle of 115.44o. To resolve the jet-like flow problem and poor distribution of the flow temperature at the diffuser outlet, the study suggested the use of guide-vanes into the diffuser. The study employed CFD simulation by ANSYS-FLUENT software to analyze the flow and thermal process in the diffuser. Three different shapes of guide vanes; block-shaped, oval-shaped and airfoil-shaped were considered in this study and at different vanes diffusion angles, as well as vane-less case, which was adopted as the bench mark case. The simulation results of the velocity, temperature and pressure at the diffuser outlet were compared for all cases. It was found that the guide vanes with symmetrical airfoil profile provided the best performance with most uniform distribution at the outlet of the diffuser. Also, the airfoil-shaped guide vanes resulted in lower pressure losses compared to the block-shaped and oval-shaped guide vanes. According to the analysis results, the diffuser was redesigned to improve the diffusion and temperature distribution across the diffuser outlet.