bluuebunny/crossref_metadata_2025 huggingface dataset:
Initiation of a Proto‐transform Fault Prior to Seafloor Spreading
Authors: Illsley‐Kemp F. , Bull J. M. , Keir D. , Gerya T. , Pagli C. , Gernon T. , Ayele A. , Goitom B. , Hammond J. O. S. , Kendall J. M.
Published: December 2018

Transform faults are a fundamental tenet of plate tectonics, connecting offset extensional segments of mid‐ocean ridges in ocean basins worldwide. The current consensus is that oceanic transform faults initiate after the onset of seafloor spreading. However, this inference has been difficult to test given the lack of direct observations of transform fault formation. Here we integrate evidence from surface faults, geodetic measurements, local seismicity, and numerical modeling of the subaerial Afar continental rift and show that a proto‐transform fault is initiating during the final stages of continental breakup. This is the first direct observation of proto‐transform fault initiation in a continental rift and sheds unprecedented light on their formation mechanisms. We demonstrate that they can initiate during late‐stage continental rifting, earlier in the rifting cycle than previously thought. Future studies of volcanic rifted margins cannot assume that oceanic transform faults initiated after the onset of seafloor spreading.
Daytime Ionospheric TEC Weather Study Over Latin America
Authors: Romero‐Hernandez E. , Denardini C. M. , Takahashi H. , Gonzalez‐Esparza J. A. , Nogueira P. A. B. , de Pádua M. B. , Lotte R. G. , Negreti P. M. S. , Jonah O. F. , Resende L. C. A. , Rodriguez‐Martinez M. , Sergeeva M. A. , Barbosa Neto P. F. , de la Luz V. , Galera Monico J. F. , Aguilar‐Rodriguez E.
Published: December 2018

The present work is the first of a two‐part weather study of the ionospheric Total Electron Content (TEC), based on data collected by four ground‐based Global Navigation Satellite System networks that cover the whole Latin America from the Patagonia to the north of Mexico. From the best of our knowledge, the maps presented here are the first TEC maps obtained using ground‐based data that covers the entire Latin America region, which represent an advance to the space weather monitoring and forecasting of the ionosphere. This work provides a qualitative and quantitative daytime analysis of the ionospheric TEC variation, which encompasses: (a) the response of TEC to the solar flux at midday; (b) the seasonal variation of TEC in different latitudinal ranges; and (c) the North‐South asymmetry of TEC over Latin America. The response to the solar flux is based on day‐to‐day TEC variations during two periods of different solar activity conditions: 2011 (ascending phase) and 2014 (maximum). The approximations of meridional wind component derived from Horizontal Wind Model‐14 model and hmF2 obtained from International Reference Ionosphere model were used. Equinoctial asymmetries with an opposite configuration in high and moderate solar activity were identified in the TEC variation. For 2011, it was related to the solar flux change. However, in 2014, according to the hmF2 variation, the influence of neutral wind becomes dominant. Among the results, we highlight an absence of winter anomaly in the Northern Hemisphere in 2014 and a stronger annual anomaly for latitudes under −20∘.
Density‐Temperature Synchrony in the Hydrostatic Thermosphere
Authors: Kodikara Timothy , Carter Brett , Norman Robert , Zhang Kefei
Published: December 2018

The paper presents a detailed analysis of the density‐temperature (ρ‐T) synchrony in the thermosphere using a hydrostatic general circulation model. The numerical models in general offer not only great potential for forecasting the transient response of the thermosphere but also are excellent tools for understanding the driving mechanisms of various thermospheric trends and features. This study investigates and isolates the dependency of the ρ‐T synchrony on the season, altitude, space weather, high‐latitude electrodynamics, and the lower atmospheric tidal spectrum. The results demonstrate that the previously reported ρ‐T synchrony begins around 300‐km (350‐km) altitude at the equator (high latitudes). The effect of the lower atmospheric tidal spectrum on the ρ‐T synchrony patterns seems to be only marginal and more noticeable during the equinox months. The study demonstrates that the ρ‐T phase lag is larger in the high latitudes of the summer hemisphere and evolves through the day and is attributable to ion drag and temperature fluctuations via soft particle precipitation. The study provides physical insights into how the winds contribute to the ρ‐T synchrony. In addition, the results show that geomagnetic activity contributes significantly to the ρ‐T synchrony; the underlying mechanism may be related to temperature enhancements in the high latitudes via Joule heating and associated nonlinear interactions. While the ρ‐T phase lags attributable to different solar activity levels are modest, the solar heating is the primary source that maintains the ρ‐T synchrony in the low/middle latitudes via upward propagating thermal tides.
Variation of Small‐Scale Gravity Wave Activity in the Ionosphere During the Major Sudden Stratospheric Warming Event of 2009
Authors: Nayak Chinmaya , Yiğit Erdal
Published: December 2018

The present study investigates the effect of the major sudden stratospheric warming (SSW) event of 2009, on the small‐scale gravity wave (GW) activity in the ionosphere. Small‐scale fluctuations with time periods within the range of 10–90 min observed in Global Positioning System total electron content (TEC) data have been used as a proxy for GW activity in the ionosphere. TEC data from five longitudinally separated Global Positioning System stations located around 60∘N latitude have been utilized for this purpose. In the initial phase of the major warming, when the stratospheric conditions are similar to a minor warming during which the mean zonal flow starts to weaken, the ionopsheric GW activity tends to increase. However, during the peak phase of the SSW, as the zonal mean wind starts to reverse its direction, and after the peak warming, as the winds remain weak, conditions are less favorable for upward propagation of a spectrum of GWs, and thus the ionospheric GW activity is reduced, as seen from the behavior of the small‐scale TEC fluctuations during the latter period of the SSW. Similar reduction in GW activity is also observed in the middle atmosphere (65–100 km) as seen from GWs derived from SABER (Sounding of the Atmosphere using Broadband Emission Radiometry) temperature profiles. The reductions in GW activity is more prominent during local daytime as compared to nighttime period. The reduction in GW activity shows a longitudinal variation with some locations showing relatively more reduction in the GW activity as compared to others.
Earthquake Early Warning Using Future Generation Gravity Strainmeters
Authors: Juhel K. , Ampuero J. P. , Barsuglia M. , Bernard P. , Chassande‐Mottin E. , Fiorucci D. , Harms J. , Montagner J.‐P. , Vallée M. , Whiting B. F.
Published: December 2018

Recent studies reported the observation of prompt elastogravity signals during the 2011 M9.1 Tohoku earthquake, recorded with broadband seismometers and gravimeter between the rupture onset and the arrival of the seismic waves. Here we show that to extend the range of magnitudes over which the gravity perturbations can be observed and reduce the time needed for their detection, high‐precision gravity strainmeters under development could be used, such as torsion bars, superconducting gradiometers, or strainmeters based on atom interferometers. These instruments measure the differential gravitational acceleration between two seismically isolated test masses and are initially designed to observe gravitational waves around 0.1 Hz. Our analysis involves simulations of the expected gravity strain signals generated by fault rupture, based on an analytical model of gravity perturbations in a homogeneous half‐space. We show that future gravity strainmeters should be able to detect prompt gravity perturbations induced by earthquakes larger than M7, up to 1,000 km from the earthquake centroid within P waves travel time and up to 120 km within the first 10 s of rupture onset, provided a sensitivity in gravity strain of 10−15 Hz−1/2 at 0.1 Hz can be achieved. Our results further suggest that, in comparison to conventional P wave‐based earthquake‐early warning systems, gravity‐based earthquake‐early warning systems could perform faster detections of large offshore subduction earthquakes (at least larger than M7.3). Gravity strainmeters could also perform earlier magnitude estimates, within the duration of the fault rupture, and therefore complement current tsunami warning systems.
Fluorine-free water-in-ionomer electrolytes for sustainable lithium-ion batteries
Authors: He Xin , Yan Bo , Zhang Xin , Liu Zigeng , Bresser Dominic , Wang Jun , Wang Rui , Cao Xia , Su Yixi , Jia Hao , Grey Clare P. , Frielinghaus Henrich , Truhlar Donald G. , Winter Martin , Li Jie , Paillard Elie
Published: December 2018

The continuously increasing number and size of lithium-based batteries developed for large-scale applications raise serious environmental concerns. Herein, we address the issues related to electrolyte toxicity and safety by proposing a “water-in-ionomer” type of electrolyte which replaces organic solvents by water and expensive and toxic fluorinated lithium salts by a non-fluorinated, inexpensive and non-toxic superabsorbing ionomer, lithium polyacrylate. Interestingly, the electrochemical stability window of this electrolyte is extended greatly, even for high water contents. Particularly, the gel with 50 wt% ionomer exhibits an electrochemical stability window of 2.6 V vs. platinum and a conductivity of 6.5 mS cm−1 at 20 °C. Structural investigations suggest that the electrolytes locally self-organize and most likely switch local structures with the change of water content, leading to a 50% gel with good conductivity and elastic properties. A LiTi2(PO4)3/LiMn2O4 lithium-ion cell incorporating this electrolyte provided an average discharge voltage > 1.5 V and a specific energy of 77 Wh kg−1, while for an alternative cell chemistry, i.e., TiO2/LiMn2O4, a further enhanced average output voltage of 2.1 V and an initial specific energy of 124.2 Wh kg−1 are achieved.
MoVE identifies metabolic valves to switch between phenotypic states
Authors: Venayak Naveen , von Kamp Axel , Klamt Steffen , Mahadevan Radhakrishnan
Published: December 2018

Metabolism is highly regulated, allowing for robust and complex behavior. This behavior can often be achieved by controlling a small number of important metabolic reactions, or metabolic valves. Here, we present a method to identify the location of such valves: the metabolic valve enumerator (MoVE). MoVE uses a metabolic model to identify genetic intervention strategies which decouple two desired phenotypes. We apply this method to identify valves which can decouple growth and production to systematically improve the rate and yield of biochemical production processes. We apply this algorithm to the production of diverse compounds and obtained solutions for over 70% of our targets, identifying a small number of highly represented valves to achieve near maximal growth and production. MoVE offers a systematic approach to identify metabolic valves using metabolic models, providing insight into the architecture of metabolic networks and accelerating the widespread implementation of dynamic flux redirection in diverse systems.
Overall water splitting by graphdiyne-exfoliated and -sandwiched layered double-hydroxide nanosheet arrays
Authors: Hui Lan , Xue Yurui , Huang Bolong , Yu Huidi , Zhang Chao , Zhang Danyan , Jia Dianzeng , Zhao Yingjie , Li Yongjun , Liu Huibiao , Li Yuliang
Published: December 2018

It is of great urgency to develop efficient, cost-effective, stable and industrially applicable electrocatalysts for renewable energy systems. But there are still few candidate materials. Here we show a bifunctional electrocatalyst, comprising graphdiyne-exfoliated and -sandwiched iron/cobalt layered double-hydroxide nanosheet arrays grown on nickel foam, for the oxygen and hydrogen evolution reactions. Theoretical and experimental data revealed that the charge transport kinetics of the structure were superior to iron/cobalt layered double-hydroxide, a prerequisite for improved electrocatalytic performance. The incorporation with graphdiyne increased the number of catalytically active sites and prevented corrosion, leading to greatly enhanced electrocatalytic activity and stability for oxygen evolution reaction, hydrogen evolution reaction, as well as overall water splitting. Our results suggest that the use of graphdiyne might open up new pathways for the design and fabrication of earth-abundant, efficient, functional, and smart electrode materials with practical applications.
Functional genomic analysis identifies miRNA repertoire regulating C. elegans oocyte development
Authors: Minogue Amanda L. , Tackett Michael R. , Atabakhsh Elnaz , Tejada Genesis , Arur Swathi
Published: December 2018

Oocyte-specific miRNA function remains unclear in mice and worms because loss of Dgcr8 and Dicer from mouse and worm oocytes, respectively, does not yield oogenic defects. These data lead to several models: (a) miRNAs are not generated in oocytes; (b) miRNAs are generated but do not perform an oogenic function; (c) functional oocyte miRNAs are generated in a manner independent of these enzymes. Here, we test these models using a combination of genomic, expression and functional analyses on the C. elegans germline. We identify a repertoire of at least twenty-three miRNAs that accumulate in four spatial domains in oocytes. Genetic tests demonstrate that oocyte-expressed miRNAs regulate key oogenic processes within their respective expression domains. Unexpectedly, we find that over half of the oocyte-expressed miRNAs are generated through an unknown Drosha independent mechanism. Thus, a functional miRNA repertoire generated via Drosha dependent and independent pathways regulates C. elegans oocyte development.
Pathogenic copy number variants that affect gene expression contribute to genomic burden in cerebral palsy
Authors: Corbett Mark A. , van Eyk Clare L. , Webber Dani L. , Bent Stephen J. , Newman Morgan , Harper Kelly , Berry Jesia G. , Azmanov Dimitar N. , Woodward Karen J. , Gardner Alison E. , Slee Jennie , Pérez-Jurado Luís A. , MacLennan Alastair H. , Gecz Jozef
Published: December 2018

Cerebral palsy (CP) is the most frequent movement disorder of childhood affecting 1 in 500 live births in developed countries. We previously identified likely pathogenic de novo or inherited single nucleotide variants (SNV) in 14% (14/98) of trios by exome sequencing and a further 5% (9/182) from evidence of outlier gene expression using RNA sequencing. Here, we detected copy number variants (CNV) from exomes of 186 unrelated individuals with CP (including our original 98 trios) using the CoNIFER algorithm. CNV were validated with Illumina 850 K SNP arrays and compared with RNA-Seq outlier gene expression analysis from lymphoblastoid cell lines (LCL). Gene expression was highly correlated with gene dosage effect. We resolved an additional 3.7% (7/186) of this cohort with pathogenic or likely pathogenic CNV while a further 7.7% (14/186) had CNV of uncertain significance. We identified recurrent genomic rearrangements previously associated with CP due to 2p25.3 deletion, 22q11.2 deletions and duplications and Xp monosomy. We also discovered a deletion of a single gene, PDCD6IP, and performed additional zebrafish model studies to support its single allele loss in CP aetiology. Combined SNV and CNV analysis revealed pathogenic and likely pathogenic variants in 22.7% of unselected individuals with CP.
F-doped TiO2 microporous coating on titanium with enhanced antibacterial and osteogenic activities
Authors: Zhou Jianhong , Li Bo , Han Yong
Published: December 2018

To enhance bacterial resistance and osteogenesis of titanium (Ti) -based implants, TiO2/calcium-phosphate coatings (TiCP) doped with various amounts of fluorine (F) (designated as TiCP-F1, TiCP-F6, and TiCP-F9) were prepared on Ti by micro-arc oxidation. The F doped TiCP coatings possess a microporous structure (pore size of 3–4 μm in average diameter) which is evenly covered by nano-grains of 30–60 nm in size. Successful F incorporation into TiCP was determined by X-ray photoelectron spectroscopy, and it shows weak influence on the microstructure, phase compositions, surface roughness and wettability of TiCP. All the coatings bonded firmly to the Ti substrates and showed enduring high adhesion strength in biological circumstances. The bacterial resistance and osteogenesis of the coatings were evaluated by implanting testing materials in vitro and in an infected rabbit model caused by bacteria. Both the in vitro and in vivo results indicated that TiCP and TiCP-F1 were of much higher osteogenic activity compared with Ti but lacking of bacterial resistance, whereas TiCP with high F addition (TiCP-F6 and TiCP-F9) exhibited both dramatically improved bacterial resistance and osteogenesis. In summary, TiCP-F6 possessed the best antibacterial and osteogenic activities, especially exhibited excellent osseointegration efficacy in the infected rabbit model.
Moisture-tolerant supermolecule for the stability enhancement of organic–inorganic perovskite solar cells in ambient air
Authors: Wei Dong , Huang Hao , Cui Peng , Ji Jun , Dou Shangyi , Jia Endong , Sajid Sajid , Cui Mengqi , Chu Lihua , Li Yingfeng , Jiang Bing , Li Meicheng
Published: December 2018

Long-term stability of the perovskite materials and devices in high humidity could be improved by the moisture-tolerant supermolecules.
Atomically thick Ni(OH)2 nanomeshes for urea electrooxidation
Authors: Ding Yu , Li Ying , Xue Yuanyuan , Miao Boqiang , Li Shuni , Jiang Yucheng , Liu Xien , Chen Yu
Published: December 2018

Atomically thick two-dimensional Ni(OH)2 nanomeshes with 1.7 nm thickness and numerous nanoholes are handily achieved by a simple NaBH4 assisted cyanogel hydrolysis method, which show outstanding electrocatalytic activity for the urea oxidation reaction in the alkaline electrolyte.
Voltage-reduced low-defect graphene oxide: a high conductivity, near-zero temperature coefficient of resistance material
Authors: Silverstein Kevin W. , Halbig Christian E. , Mehta Jeremy S. , Sharma Anju , Eigler Siegfried , Mativetsky Jeffrey M.
Published: December 2018

A highly conductive, low temperature coefficient of resistance nanomaterial was generated by using low-defect graphene oxide in conjunction with voltage-reduction.
Charge transfer dynamics in CsPbBr3 perovskite quantum dots–anthraquinone/fullerene (C60) hybrids
Authors: Mandal Sadananda , George Lijo , Tkachenko Nikolai V.
Published: December 2018

An advantage of colloidal quantum dots, particularly perovskite quantum dots (PQDs), as photoactive components is that they easily form complexes with functional organic molecules, which results in hybrids with enriched photophysical properties.
Bioaccumulation of polystyrene nanoplastics and their effect on the toxicity of Au ions in zebrafish embryos
Authors: Lee Wang Sik , Cho Hyun-Ju , Kim Eungwang , Huh Yang Hoon , Kim Hyo-Jeong , Kim Bongsoo , Kang Taejoon , Lee Jeong-Soo , Jeong Jinyoung
Published: December 2018

Size- and dose-dependent bioaccumulation of polystyrene nanoplastics influence on the toxicity of gold ion in zebrafish embryos.
A cascade process for the synthesis of ortho-formyl allyl aryl ethers and 2H-chromen-2-ol derivatives from arynes via trapping of o-quinone methide with an activated alkene
Authors: Sharma Abhilash , Gogoi Pranjal
Published: December 2018

A transition-metal free synthetic strategy for the direct synthesis of ortho-formyl substituted allyl aryl ethers and 2H-chromen-2-ol derivatives via a cascade three-component coupling of arynes, activated alkene and N,N-dimethylformamide.
Visible light driven metal-free intramolecular cyclization: a facile synthesis of 3-position substituted 3,4-dihydroisoquinolin-1(2H)-one
Authors: Zou Shuai , Geng Shu , Chen Lina , Wang Haitao , Huang Feng
Published: December 2018

Visible light driven metal-free intramolecular cyclization: a facile synthesis of 3-position substituted 3,4-dihydroisoquinolin-1(2H)-one.
One-pot stapling of interchain disulfides of antibodies using an isobutylene motif
Authors: Sun Shuang , Akkapeddi Padma , Marques Marta C. , Martínez-Sáez Nuria , Torres Vukosava M. , Cordeiro Carlos , Boutureira Omar , Bernardes Gonçalo J. L.
Published: December 2018

Stable monoclonal antibodies are generated by the mild and efficient re-bridging of interchain disulfides using an isobutylene motif. Effector functions and pharmacokinetics of the stapled antibodies are maintained at a similar level as their native forms.
In vitro reconstitution of the biosynthetic pathway of 3-hydroxypicolinic acid
Authors: Yun Xuan , Zhang Qian , Lv Meinan , Deng Hai , Deng Zixin , Yu Yi
Published: December 2018

Four enzymes direct the biosynthesis of 3-hydroxypicolinic acid, an important building block of bacterial natural products.
Recent advances in functional nanostructured materials for bone-related diseases
Authors: Li Anqi , Xie Jing , Li Jianshu
Published: December 2018

This article reviews the recent advances in the development of nanostructured materials for bone-related diseases such as osteoporosis and osteoarthritis.
Two-way rewritable and stable photonic patterns enabled by near-infrared laser-responsive shape memory photonic crystals
Authors: Chang Pingnan , Niu Wenbin , Qu Lingcheng , Zhang Shufen
Published: December 2018

A new type of near-infrared laser responsive shape memory photonic crystals that enable the fabrication of two-way rewritable photonic patterns is reported.
The tumor-suppressive function of miR-1296-5p by targeting EGFR and CDK6 in gastric cancer
Authors: Jia Yan , Zhao Lian-Mei , Bai Han-Yu , Zhang Cong , Dai Su-Li , Lv Hui-lai , Shan Bao-En
Published: December 2018

We aimed to confirm the role of miR-1296-5p in gastric cancer and to identify its target genes. The expression of miR-1296-5p was measured in gastric cancer tissues and cell lines. The function of miR-1296-5p was examined by the overexpression and inhibition of its expression in typical gastric cell lines as well as SGC-7901 and MGC-803 cells. The targets of miR-1296-5p were identified by a luciferase activity assay. We found that miR-1296-5p was down-regulated in gastric cancer tissue and cell lines, and low expression levels of miR-1296-5p were associated with advanced clinical stage. Moreover, miR-1296-5p inhibited cell proliferation, migration, and invasion in SGC-7901 and MGC-803 cells. Then, we identified CDK6 and EGFR as novel targets of miR-1296-5p by a luciferase activity assay. Furthermore, the overexpression of miR-1296-5p suppressed the expression of CDK6 and EGFR. Our results indicated a tumor-suppressive role of miR-1296-5p through the translational repression of oncogenic CDK6 and EGFR in gastric cancer.
Evaluation of a Protocol for Integrated Speech Audiometry
Authors: Punch Jerry , Rakerd Brad
Published: December 2018

Purpose

This project was aimed at evaluating the reliability, validity, and clinical utility of a protocol for integrated measurements of the most comfortable level (MCL) and uncomfortable level (UCL) for speech, in combination with the speech recognition threshold (SRT). We also evaluated the validity of using spondee words when measuring speech MCL and UCL.

Method

In a randomized block design, equal numbers of women and men with normal hearing, aged 18–29 years, were assigned to each of 3 experimental stimulus conditions: spondee singlets, spondee triplets, or connected discourse (n= 12 per group). Following measurement of the SRT, a modified method of limits was employed to establish, on a 7-point loudness rating scale, an ascending MCL, a descending MCL, and an ascending UCL. A single instructional set covered all loudness measurements. Test times were tracked electronically to assess clinical efficiency. All test conditions were repeated during each of 2 separate test sessions.

Results

Mean SRTs, MCLs, and UCLs across the 3 different experimental groups were found not to differ statistically or clinically (mean differences < 5 dB). Intrasession and intersession reliability for the various measures were excellent, and testing of all listeners was completed in a timely manner. In a follow-up experiment with adults with normal hearing who were only a decade older than participants in our main experiment, the older group was found to have significantly higher MCLs and UCLs.

Conclusions

Spondee words can be used routinely to obtain reliable, valid, and clinically efficient measures of MCLs and UCLs for speech, in a protocol combined with the SRT. Spondees, presented singly, yielded the greatest level of efficiency overall. Results support a recommendation to obtain an ascending measurement of MCL prior to a descending measurement and to establish the MCL by averaging the 2 values.
Performance analysis and control of fractional‐order positive systems
Authors: Wang Cuihong , Zhao Yafei
Published: December 2018

Unlike a general integer‐order linear system, the and norms of its state and output variables may not be convergent in an infinite time interval even if the concerned fractional‐order linear system is asymptotically stable or even Mittag–Leffler stable. Therefore, this study mainly investigates the analysis and synthesis of and performances in a finite time interval for a class of fractional‐order positive systems. The performance problem in the infinite time interval is also concerned since the boundness of the norm of the state and output variables can be guaranteed in the infinite time interval if the concerned fractional‐order positive system is asymptotical stable. The and performance characterisations are expressed by linear programming and performance characterisation is expressed in terms of linear matrix inequality with a diagonal positive definite solution. Based on these performance conditions, the problems of stabilisation by a state feedback controller with ‐gain guaranteed are solved for fractional‐order positive systems. An example is presented to show the effectiveness of the proposed methods in this study.
Improving road safety and user experience by employing dynamic in‐vehicle information systems
Authors: Galarza Miguel , Paradells Josep
Published: December 2018

Modern vehicular infotainment systems are becoming increasingly complex and are embracing a wide range of functionalities. Interacting with some of these functionalities, while driving, may increase the driver's workload and affect the execution of primary driving tasks. This article addresses this issue and proposes a practical application that could help overcome the problem as well as improve the driving experience. The applied method consists of developing a system capable of estimating the driving complexity in real time using variables already available in current vehicles, and responding according to the complexity reference, to apply countermeasures to the infotainment system. The intended purpose is to facilitate the interaction with the functionalities and reducing the amount of information offered to the driver in complex scenarios. A baseline system was built and tested, demonstrating the feasibility of its implementation in current vehicles.
Stability analysis of grid‐connected PV generation with an adapted reactive power control strategy
Authors: Yan Gangui , Cai Yuru , Jia Qi , Liang Shuai
Published: December 2018

The static VAR compensator is widely applied in large‐scale grid‐connected photovoltaic (PV) generation to participate in voltage regulation of power system, which ignores the reactive power regulation capability of PV inverter. In this study, firstly, the constraints of maximum operating current and output voltage's amplitude of PV inverter are considered, and the reactive power regulation capability of the PV generation is evaluated; secondly, an active participation in voltage regulation and control strategy of PV generation is proposed considering reactive power demand of system. This control method through the real‐time detection and comparison with reference value of point of common coupling (PCC) voltage, automatically obtain the reactive demand to maintain PCC voltage by PI controller and realises the dynamic adjustment; finally, a time‐domain small‐signal model for PV generation is established, and based on this small‐signal model, eigenvalue analysis is employed to study the influence of the grid strength, operating condition, and the reactive power control strategy on operating stability. Based on the time‐domain simulation example in EMTDC/PSCAD, the validity of the theoretical analysis and the feasibility of the control strategy are verified.
Research on AC & DC hybrid power supply system with high‐proportion renewable energy of data centre
Authors: He Wenzhi , Xue Feng , Zheng Fenglei , Zhou Yongyan , Liu Kun , Tian Yipan
Published: December 2018

In the background of the energy Internet, the number of data centres is increasing, aiming at the shortcomings of power supply and reliability in power supply system of traditional data centre and the development trend of green data centres. This article proposes an AC & DC hybrid power supply system with high‐proportion renewable energy. The system includes photovoltaic generation, wind power generation, photothermal power generation, thermal utilisation system, power storage system, and different types of loads. Therein, a multi‐port power electronic transformer is used to realise AC & DC multi‐level mixing system with high proportion of variety of distributed renewable energy. Thereafter, the power supply, power grid, and the load can efficiently complement each other by using the integrated energy storage system such as electricity storage and heat storage. In detail, the rationality and functionality of the AC & DC hybrid power system are analysed through the system simulation and power supply reliability calculation. Moreover, the results show that the proposed hybrid power supply can effectively improve the impact of high‐proportion renewable energy access to the grid and provide a new design scheme for the green data centre.
Measuring precise radial velocities and cross-correlation function line-profile variations using a Skew Normal density
Authors: Simola U. , Dumusque X. , Cisewski-Kehe J.
Published: December 2018

Context.Stellar activity is one of the primary limitations to the detection of low-mass exoplanets using the radial-velocity (RV) technique. Stellar activity can be probed by measuring time-dependent variations in the shape of the cross-correlation function (CCF). It is therefore critical to measure with high-precision these shape variations to decorrelate the signal of an exoplanet from spurious RV signals caused by stellar activity.

Aims.We propose to estimate the variations in shape of the CCF by fitting a Skew Normal (SN) density which, unlike the commonly employed Normal density, includes a Skewness parameter to capture the asymmetry of the CCF induced by stellar activity and the convective blueshift.

Methods.We compared the performances of the proposed method to the commonly employed Normal density using both simulations and real observations with different levels of activity and signal-to-noise ratios.

Results.When considering real observations, the correlation between the RV and the asymmetry of the CCF and between the RV and the width of the CCF are stronger when using the parameters estimated with the SN density rather than those obtained with the commonly employed Normal density. In particular, the strongest correlations have been obtained when using the mean of the SN as an estimate for the RV. This suggests that the CCF parameters estimated using a SN density are more sensitive to stellar activity, which can be helpful when estimating stellar rotational periods and when characterizing stellar activity signals. Using the proposed SN approach, the uncertainties estimated on the RV defined as the median of the SN are on average 10% smaller than the uncertainties calculated on the mean of the Normal. The uncertainties estimated on the asymmetry parameter of the SN are on average 15% smaller than the uncertainties measured on the Bisector Inverse Slope Span (BIS SPAN), which is the commonly used parameter to evaluate the asymmetry of the CCF. We also propose a new model to account for stellar activity when fitting a planetary signal to RV data. Based on simple simulations, we were able to demonstrate that this new model improves the planetary detection limits by 12% compared to the model commonly used to account for stellar activity.

Conclusions.The SN density is a better model than the Normal density for characterizing the CCF since the correlations used to probe stellar activity are stronger and the uncertainties of the RV estimate and the asymmetry of the CCF are both smaller.
Applications for mobile devices informing about threats
Authors: Tuśnio Norbert
Published: December 2018

Following article contains a description of selected applications for mobile devices, such as smartphones or tablets, which tasks are to inform the public about hazards, as well as calling for help. The focus was on software widely available in online app store (Google Play), and due to the imperfections of the programs mentioned, it was decided to develop own application called “Rescue Application Volunteer”. Its main purpose and functionality covers help summoning for oneself and other people, also marking places on map where e.g. fire is starting or local threat is arising. Various solutions of these problems were given and issues related to the protection of personal data in this type of applications were discussed.
Geoinformational system of rescue services
Authors: Yemelyanenko Sergiy , Rudyk Yuriy , Kuzyk Andriy , Yakovchuk Roman
Published: December 2018

Geoportal is an indispensable tool for processing data related to city infrastructure, life support systems; for the analysis of statistics of fires and other emergency situations in the city; to create thematic layers of electron-vector maps showing the city’s infrastructure and other information necessary for the management of the SNS units; for identification of fire risks for residential buildings and public buildings of Lviv city and mapping them according to the risk levels in the form of a risk map. The analysis of the city’s infrastructure allows us to study in detail the problematic issues related to fire and technological safety. The geoportal and its cartographic information of the information will allow the head of the rescue unit, during the post-emergency situation, to find the information necessary for the effective performance of rescue operations and to assess the potential risks.
Hazards associated with municipal waste storage. Vol. I
Authors: Dmochowska Anna
Published: December 2018

Depositing municipal waste in a responsible and controlled manner in landfills allows their decomposition to stabilized material. However, there are many environmental risks during operation and stabilization after landfill closure. These include: dusts, odors, potential fires associated with the presence of landfill gas and it is microbiological hazards and leachates. The latter are also generated many years after closure and reclamation of the landfill. In the event of a leak trough the anti-filtration shutter, toxic compounds found in the leachates can migrate and contaminate to groundwater. The article presents the quantitative and qualitative analysis of leachates in the final operational period of the landfill and after its closure. In both cases, the chromatographic analysis was carried out using the same conditions, i.e. solvent, extraction time, chromatograph and conditions for chromatographic analysis of samples. Physical and chemical leachate examinations were performed on the basis of valid standards. Their results show that the waste deposit is subject to increasingly advanced biodegradation processes of organic compounds. The values of such indicators as COD and BZT5 are decreasing. However, they remain quite significant, which indicates the presence of hard-to decompose and newly compounds in the leachates.
Effect of graphite sizes and carbon black content on flowability of the injection molded conductive composite material
Authors: Mahyoedin Yovial , Sahari Jaafar , Mukhtar Andanastuti , Mohammad Norhamidi , Suryadimal
Published: December 2018

This study is to investigate the flowability of the injection molded conductive composite material containing filler content from 70 up to 80 wt% by using spiral mold. Several moulding compounds, containing polypropylene (PP) as a matrix and graphite (G) and carbon black (CB) as conductive fillers prepared by melt compounding using twin-screw extruder. Carbon black is added as much as 10% and 20% respectively, in order to improve the electrical conductivity of composite material. Results show that the flowability of injection molded conductive composite material decreases with decreasing graphite size and with increasing filler (graphite and carbon black) content. It was found that composites containing G with particle size distribution (≤100 μm) entirely exhibits a relatively higher flowability, in the range of 10.67–6.21 cm, compared to the small size (25-60 μm), in which flowability is in the range of 5.23–3.37 cm. An attempt to combine carbon black as second filler with the PP and G found that composites containing CB showed decreased flowability of the injection molded conductive composite material, especially when the electrical conductivity formed through the resin. Results indicate that the flowability of the injection molded conductive composite material is an important design parameter to fabricate cost-effective, large, or thin composite bipolar plates.
Analysis of Characteristics Over Current Relay and Ground Fault Relay on Feeder Rayon Tabing
Authors: Arzul  , Darmana Ija , Erliwati  , Salvayer Adiv Rama , Yetno Tris Safri
Published: December 2018

The reliability of power distribution of PT PLN (Persero) branch of Padang especially in Rayon Tabing most of the repeaters is still not optimal. This is due to an uncoordinated protection relay on each feeder. One effort made to improve the reliability of electric power is to rearrange the protection of overcurrent relays and ground disturbance relays on the feeder. So coordinated with each other well and is expected if there is interference in one of the repeater will not bring black out on other repeater. In this research we analyzed short circuit current at 20 kV side. From the analysis results obtained new relay protection settings based on the calculation of short-circuit current settings and compare the results with existing protection relays. By making efforts to improve the reliability of electric power is to rearrange the protection relay on each feeder. Based on short circuit current analysis on each repeater, the largest short circuit in 3 phase, 2 phase, and 1 phase disturbance is located at 1% disturbance location and the smallest disturbance is at 100% disturbance location. It can be concluded that the farther the location of the disturbance that occurs the smaller the disturbance, and vice versa, if the location of the disturbance that occurs closer then the greater the noise flow.
Intervention Selection to the Awareness of Energy-Saving Behavior in the Public Sector
Authors: Linda Rozza , Susanti Lusi , Zadry Hilma Raimona
Published: December 2018

Nowadays Indonesia is facing energy scarcity and still struggling with finding new energy resources. No other ways the employee have to use the currently available energy wisely. However wasteful behavior in energy use is still often seen in public sectors like government/private buildings, schools/campuses, hospital, and others. Various effort (such as energy saving campaign through mass media, pamphlet, etc) have been made by the building managers or owners to encourage users energy-saving behavior through various channels but found ineffective. Therefore, this study was conducted to select the alternative intervention to increase the awareness of energy-saving behavior in Indonesia by referring to the conceptual model of ABC (Antecedents-Behavior-Consequences) behavioral pattern. Several samples were taken from several public buildings, including government/private institutions, schools/campuses, hospital and mosques in Padang city. Data were collected through questionnaires filled by 30 respondents in each sector. The result shows that the phase of antecedent, the most appropriate type of intervention to build awareness of energy saving behavior for people is by making strong commitments in each building sector and the local government. In the consequence phase there are two criteria selected: reward and finance/legislation. The reward can be delivered for example, through providing a discount voucher or tax reduction. As for the consequence on finance/legislation can be done by creating and controlling the implementation of government regulations that are related to the electricity saving problem in public sector.
Strategy Design to Improve the Implementation of Supply Chain Management in Food SMEs
Authors: Windaryanti Agustina , Dachyar M. , Farizal
Published: December 2018

Food and beverage industry serves as one of the primary industries by the Ministry of Industry for industrial development plan until 2035. To improve the competitiveness of food SMEs, the strategy of implementing supply chain management is designed. The purpose of this research is to obtain strategy recommendations for the implementation of supply chain management in food SMEs. The literature study was conducted to find out the criteria, sub-criteria, and strategies that need to be implemented in improving the supply chain management of the food SMEs. Analytical Network Process (ANP) method is used to find the weight of criteria, sub-criteria, and strategy of implementing supply chain management. Criteria, sub-criteria, and strategies are judged by seven experts. This research obtained five criteria, twelve sub-criteria, and twenty-three strategies for the implementation of supply chain management. The result of data processing shows strategy that has the highest weight is to coordinate the logistics department with other functions in the company.
Application of Compound Bonding Based On Augmented Reality
Authors: Setiawan Alexander , Rostianingsih Silvia , Widodo Timotitus Reinaldo
Published: December 2018

Augmented reality technology is very important in visualizing real objects or concepts. The advancement of computing equipment enables 3D modelling to be performed virtually with relatively easy processes. The appearance of 3D models in virtual is very interesting because it can be combined with interactive multimedia applications so that users can control the course of the application as needed. This augmented reality application has been through process testing, system testing on different mobile devices, and marker testing. The results of process testing indicate that every process on the application goes according to existing model design. Test results show that applications created using the library vuforia and Unity can run well. High school students show that as many as 84.6% who agree with using this application is more interesting than the usual method of learning so as to be able to recognize compound bonding using this application well.
Correlation between surface roughness and AE signals in ceramic grinding based on spectral analysis
Authors: Aulestia Viera M A , Alexandre F A , Aguiar P R , Silva R B , Bianchi E C
Published: December 2018

The study and monitoring of the workpiece surface roughness is one of the most important parameters of the grinding process. This paper proposes a method for analysing the surface condition of ground ceramic components by means of the acoustic emission (AE) signal analysis along with frequency domain techniques. Tests were performed using a surface-grinding machine equipped with a resin-bond diamond grinding wheel, where signals were collected at 2 MHz. Alumina workpieces were machined under six different depth of cut values, covering slight, medium and severe grinding conditions. Frequency content was studied in order to select bands closely related to the process conditions. An analysis of the root mean square values (RMS) of the signals was performed, seeking for a correlation with the surface roughness. Digital filters were applied to the raw signals. The RMS values filtered for two frequency bands presented a better fitting to the linear regression, which is highly desirable for setting a threshold to detect the workpiece surface conditions and implementing into a monitoring system. Results showed that the amplitude of the signals presented different characteristics in the frequency domain according to the workpiece surface condition. It was also observed a higher spectral activity in the severe grinding conditions.
Performance and emissions of si engine with octane boosters
Authors: Venkatesh Sai Vijay , Udayakumar R
Published: December 2018

In today’s world we see that the demand for gasoline and cars keep increasing and one problem which is significantly seen is that we either opt for a fuel which provides higher performance or for a fuel which provides lesser emissions. In this study we aim to provide higher performance and lower emissions by combining two chemicals or octane boosters, namely ethanol and toluene with gasoline and find out its performance and emission characteristics when compared with traditional gasoline and ethanol-gasoline blend. In this study we have made four blends which are PP, E10, E10T5 and E20T5 which are tested against two performance parameters which are Specific Fuel Consumption, Brake Thermal Efficiency with respect to brake power and emissions parameter which are Carbon Dioxide, Carbon Monoxide, Oxides of Nitrogen and Hydrocarbon with respect to brake power as well. In each of these performance and emissions parameters, the blends are compared and we find that E20T5 has the highest performance and E10T5 has the lowest emission.
Community Service Creating Applied Information System for Managing Inventory on Hotel SWK 95, Surabaya, Indonesia
Authors: Setiawan Alexander , Gunawan Andre , Utomo Kevin , Jioe Bernard Yusuf
Published: December 2018

In the ever-expanding digital information era, hotels in particular Hotel SWK 95 should start using information technology to help hotel operations to operate maximally. Hotel SWK 95 has an information system for booking rooms and others but Hotel SWK 95 does not have information system to manage Inventory like pillow, blanket, etc. So here the author has compiled and made an inventory information system to meet the needs of the Hotel SWK 95. The information system that the authors created can help in the inventory arrangements, especially as laundry systems and vendors anywhere that the hotel use to wash the laundry and schedule when the estimated laundry should be taken. And also the status, quantity, and history of the circulation of existing goods.