bluuebunny/crossref_metadata_2025 huggingface dataset:
Modifying graphene’s lattice dynamics by hot-electron injection from single gold nanoparticles
Authors: Weinhold Marcel , Chatterjee Sangam , Klar Peter J.
Published: February 2019

Two-dimensional layered materials like graphene pave the way to advanced (opto-) electronic devices. Their extraordinary properties can be further controlled employing plasmonic nanostructures. The interplay between two-dimensional material and plasmonic nanostructures yields enhanced light focusing, large absorption cross sections, and hot-carrier generation due to the excitation and decay of localized surface plasmons. However, this interplay strongly depends on the particle’s environment and geometry mandating the investigation of individual structures. Here, we show that Raman spectroscopy reveals locally resolved information about charge transfer, temperature, and strain distribution of graphene sheets in the vicinity of individual spherical gold nanoparticles. Hot-electrons are efficiently injected into graphene under resonant excitation of the localized surface plasmons of the gold nanoparticle. Additionally, heating of the graphene sheet and its intrinsic strain can be separated and quantified. Hence, the presented analysis provides unprecedented insights into the underlying microscopic physics enabling better device design in the future.
Non-empirical calculation of X-ray magnetic circular dichroism in lanthanide compounds
Authors: Ramanantoanina Harry , Studniarek Michał , Daffé Niéli , Dreiser Jan
Published: February 2019

Ligand-field density functional theory is shown to perform well for the calculation of circularly and linearly polarized X-ray absorption spectra.
Chiral hydrogen-bonded supramolecular capsules: synthesis, characterization and complexation of C70
Authors: Kohlhaas Martha , Zähres Manfred , Mayer Christian , Engeser Marianne , Merten Christian , Niemeyer Jochen
Published: February 2019

Hydrogen-bonded nanocapsules were generated by multi-component self-assembly of phosphoric acids and amidines and could be used as hosts for C70.
Advances in porous and nanoscale catalysts for viable biomass conversion
Authors: Sudarsanam Putla , Peeters Elise , Makshina Ekaterina V. , Parvulescu Vasile I. , Sels Bert F.
Published: February 2019

Solid catalysts with unique porosity and nanoscale properties play a promising role for efficient valorization of biomass into sustainable advanced fuels and chemicals.
Synthesis and iron chelating properties of hydroxypyridinone and hydroxypyranone hexadentate ligands
Authors: Zhou Tao , Kong Xiao-Le , Hider Robert C
Published: February 2019

Chelation therapy has become an important therapeutic approach for some diseases.
3D impedimetric sensors as a tool for monitoring bacterial response to antibiotics
Authors: Brosel-Oliu S. , Mergel O. , Uria N. , Abramova N. , van Rijn P. , Bratov A.
Published: February 2019

A novel strategy for selective immobilization of bacteria on a 3D impedimetric transducer for sensing antimicrobial reagents.
Selective hydrogenation of nitroarenes to amines by ligand-assisted Pd nanoparticles: influence of donor ligands on catalytic activity
Authors: Kalita Gauravjyoti D. , Sarmah Podma P. , Saikia Pallab Kr. , Saikia Lakshi , Das Pankaj
Published: February 2019

A simple and facile approach for the synthesis of tunable ligand-assisted Pd nanoparticles for selective hydrogenation of nitroarenes.
Mussel-inspired nano-silver loaded layered double hydroxides embedded into a biodegradable polymer matrix for enhanced mechanical and gas barrier properties
Authors: Mao Long , Liu Jing-yi , Zheng Si-jie , Wu Hui-qing , Liu Yue-jun , Li Zhi-han , Bai Yong-kang
Published: February 2019

A facile, green and mussel-inspired method is presented to prepare Ag loaded LDHs using a pre-synthesis PDA/TA–Fe(iii) layer as a nanoscale guide and PDA/TA itself as a reducing reagent to form uniform AgNPs on the surface of modified LDHs.
Nano Pt-decorated transparent solution-processed oxide semiconductor sensor with ppm detection capability
Authors: Kang Jingu , Kim Kyung-Tae , Jeon Seoung-Pil , Facchetti Antonio , Kim Jaekyun , Park Sung Kyu
Published: February 2019

A transparent VOC sensor based on a solution-processed IGZO for application in real-time VOC monitoring system.
A hierarchical Nb2O5@NiFe-MMO rod array, fabricated and used as a structured photocatalyst
Authors: Liu Fei , Wang Yuwei , Kong Xianggui , Lei Deqiang , Zhang Fazhi , Lei Xiaodong
Published: February 2019

The work provides a new strategy to the exploration of excellent structured photocatalysts based on transition metal oxide materials for selective aerobic oxidation of benzylamine to imine.
High-performance organic/inorganic hybrid ultraviolet p-NiO/PVK/n-ZnO heterojunction photodiodes with a poly(N-vinylcarbazole) insertion layer
Authors: Hwang Jun Dar , Fan Chun Wei
Published: February 2019

In this study, an organic poly(N-vinylcarbazole) (PVK) layer was inserted between the p-NiO and n-ZnO inorganic layers and the p-NiO/PVK/n-ZnO organic/inorganic hybrid ultraviolet heterojunction photodiode (PD) was fabricated.
Sensing carbon dioxide through a solution transparency change in gas-responsive polymers
Authors: Guo Shengwei , Zhang Hu , Lu Xili , Xiao Hui , Zhao Yue
Published: February 2019

An aqueous solution of CO2-responsive polymers is used to sense the amount of gas through either an abrupt change in transmittance at a threshold CO2 concentration or a gradual change with the increase in the CO2 concentration.
9-Borabicyclo[3.3.1]nonane: a metal-free catalyst for the hydroboration of carbodiimides
Authors: Ramos Alberto , Antiñolo Antonio , Carrillo-Hermosilla Fernando , Fernández-Galán Rafael , García-Vivó Daniel
Published: February 2019

A 9-borabicyclo[3.3.1]nonane dimer is used as the first example of metal-free catalysts for the monohydroboration of carbodiimides with pinacol borane.
Heavier pnictogens – treasures for optical electronic and reactivity tuning
Authors: Green Joshua P. , Wells Jordann A. L. , Orthaber Andreas
Published: February 2019

We highlight recent advances in organopnictogen chemistry contrasting the properties of lighter and heavier pnictogens.
N-Arylations of trifluoromethylated N-acylhydrazones with diaryliodonium salts as arylation reagents
Authors: Zhang Huaiyuan , Wang Ke-Hu , Wang Junjiao , Su Yingpeng , Huang Danfeng , Hu Yulai
Published: February 2019

A novel and efficient N-arylation of trifluoromethylated N-acylhydrazones is described by using diaryliodonium salts as arylation reagents in the presence of copper salts. A wide variety of N-aryl acylhydrazones are obtained with good to excellent yields under mild reaction conditions.
Reversible chemoselective transetherification of vinylogous esters using Fe-catalyst under additive free conditions
Authors: Parvathalu Nenavath , Agalave Sandip G. , Mohanta Nirmala , Gnanaprakasam Boopathy
Published: February 2019

An additive/Brønsted acid/base free, highly efficient and chemoselective transetherification of vinylogous esters and water mediated de-alkylation using Fe-catalyst is described.
A facile synthetic route to tungsten diselenide using a new precursor containing a long alkyl chain cation for multifunctional electronic and optoelectronic applications
Authors: Kim Jahee , Lim Yi Rang , Yoon Yeoheung , Song Wooseok , Park Bo Keun , Lim Jongsun , Chung Taek-Mo , Kim Chang Gyoun
Published: February 2019

Single source precursors for coating and subsequent thermal decomposition processes enable a large-scale, low-cost synthesis of two-dimensional transition metal dichalcogenides (TMDs).
Gram scale production of 1-azido-β-d-glucose via enzyme catalysis for the synthesis of 1,2,3-triazole-glucosides
Authors: Gorantla Jaggaiah N. , Pengthaisong Salila , Choknud Sunaree , Kaewpuang Teadkait , Manyum Tanaporn , Promarak Vinich , Ketudat Cairns James R.
Published: February 2019

The retaining β-glucosidase acid/base mutant TxGH116D593A catalyzed the production of 1-azido-β-d-glucose for synthesis of 15 1,2,3-triazole β-glucosyl derivatives.
Elucidating the reaction kinetics of lithium–sulfur batteries by operando XRD based on an open-hollow S@MnO2 cathode
Authors: Huang Shaozhuan , Liu Lixiang , Wang Ye , Shang Yang , Zhang Lin , Wang Jiawei , Zheng Yun , Schmidt Oliver G. , Yang Hui Ying
Published: February 2019

This work studied the reaction mechanism and kinetics of Li–S batteries via operando XRD and quantitative analysis based on different cathode structures.
Promising visible-light driven hydrogen production from water on a highly efficient CuCo2S4 nanosheet photocatalyst
Authors: Chauhan Meenakshi , Soni Kiran , Karthik P. E. , Reddy Kasala Prabhakar , Gopinath Chinnakonda S. , Deka Sasanka
Published: February 2019

CuCo2S4 nanosheets have been developed which work as an excellent water splitting photocatalyst with H2 evolution activity under visible light.
High electrochemical stability of a 3D cross-linked network PEO@nano-SiO2 composite polymer electrolyte for lithium metal batteries
Authors: Zhu Yinghua , Cao Jiang , Chen Hong , Yu Qipeng , Li Baohua
Published: February 2019

A novel composite polymer electrolyte (CPE) with nano-SiO2 acted as a cross-linking agent to form a 3D cross-linked network with improved electrochemical stability.
Recent advances in sensitive and rapid mercury determination with graphene-based sensors
Authors: Liu Chengbin , Chen Xiaoyan , Zong Boyang , Mao Shun
Published: February 2019

This review discusses recent advances in graphene-based Hg2+sensors with a focus on optical, electrochemical, and electronic sensing platforms.
Affine arithmetic‐based power flow algorithm considering uncertainty for hybrid AC/DC grids incorporating VSCs
Authors: Lu Fang , Du Pingjing , Liu Hongda , Liu Fanming
Published: February 2019

The randomness of new energy generation and variation in load demands bring uncertainty to large AC/DC grids. Traditional deterministic power flow equations have difficulty coping with the uncertainties of new energy generation and load. Here, an affine arithmetic (AA)‐based uncertainty power flow algorithm for hybrid AC/DC grids incorporating voltage source converters (VSCs) is presented. VSC station and DC grid models are established using AA. Diverse VSC control modes are considered in the power flow iterations. A comparison using the Monte–Carlo method shows that the proposed algorithm is able to obtain a feasible solution. The proposed method can be used by power system operators and planners to monitor and control AC/DC grids under various uncertainties.
Enhanced load frequency control: incorporating locational information for temporal enhancement
Authors: Syed Mazheruddin H. , Guillo‐Sansano Efren , Blair Steven M. , Burt Graeme M. , Prostejovsky Alexander M. , Rikos Evangelos
Published: February 2019

With the increasing penetration of renewables in power systems, frequency regulation is proving to be a major challenge for system operators using slower conventional generation, and alternative means to provide faster regulation are being actively sought. The participation of demand side management in ancillary service provision is proven in some energy markets, yet its full potential to benefit frequency regulation, including the exploitation of fast power ramping capability of some devices, is still undergoing research. In this study, a novel approach to improve the speed of response of load frequency control, a secondary frequency control approach is proposed. The proposed control is enabled by an effective location identification technique, is highly resilient to anticipated system changes such as reduction of inertia, and enables fully decentralised power system architectures. The effectiveness of the approach is demonstrated and compared to that of present day regulation control, by means of real‐time simulations incorporating appropriate time delays conducted on a five‐area reduced model of the Great Britain power system. The applicability of the method is further proven under realistic communications delays and measurements experimentally using a controller and power hardware‐in‐the‐loop setup, demonstrating its critical support for enabling the stable operation of future power systems.
Compact tunable dual/Tri‐band bandpass filters with multiple zeros
Authors: Wang Zhi‐Peng , Wang Li‐Tian , Zhou Jie , Zhang Sheng‐fang , He Ming , Ji Lu , Zhang Xu , Chen Hai‐hua , Wang Hong‐peng
Published: February 2019

Here, compact dual/tri‐band bandpass filters (BPFs) with tunable passbands are proposed. The multiband BPFs are designed by combining a BPF with tunable passband and a BPF with fixed passband using a common external coupling line. The former consists of a dual‐mode resonator loaded with varactors (DMVLR) and the latter is composed of a quad‐mode resonator (QMR). The classical analysis method of odd/even mode is employed to analyse the characteristics of the resonators. The centre frequency (CF) of the tunable passband can be easily tuned by varying the voltage imposed on the varactors. A constant absolute bandwidth (CABW) is obtained over the whole tuning range of frequency by properly adjusting loading positions of the varactors. The single and dual‐passband BPFs with fixed passband are obtained by designing the parameters of QMR appropriately. Simulation and measurement results show that the proposed BPFs are of high selectivity, and the resultant filters are of compact size. In addition, the proposed multiband BPFs have four transmission zeroes (TZs). There are two self‐adaptive TZs on both sides of the tunable passbands, which are generated by the multipath coupling structure.
Single stationary domain equivalent inverter admittance for three‐phase grid‐inverter system considering the interaction between grid and inverter
Authors: Zou Xiaoming , Du Xiong , Wang Guoning , Tai Heng‐Ming
Published: February 2019

Admittance matrix has been used to represent the characteristics of three‐phase inverter for grid‐inverter system stability evaluation in both stationary, sequence, and dq domain. For the dq domain admittance matrix, the PLL and Park transformation introduce additional dynamics during the admittance measurement that may influence the application of dq model. For the stationary and sequence domain admittance matrix, the model measurement is not affected by the above additional parts but may also encounter other difficulties in actual measurement. First, current frequency response analyser (FRA) is not able to perform two‐frequency measurement required by the admittance matrix. Second, practical limitations exist in the course of solving complex‐valued admittance matrix equations. Here, a single stationary domain equivalent admittance of three‐phase inverter for grid‐inverter system with considering the interaction between grid and inverter is defined so that the above two difficulties can be avoided. Then, an equivalent admittance model of prototype inverter is constructed for stability analysis of the grid‐inverter system using Nyquist stability criterion, instead of the generalised Nyquist criterion (GNC). The effectiveness of the proposed equivalent inverter admittance model is validated through simulation and experiment verification.
Underwater wireless power transfer system with a curly coil structure for AUVs
Authors: Yan Zhengchao , Zhang Yiming , Zhang Kehan , Song Baowei , Mi Chris
Published: February 2019

An underwater wireless power transfer system with a curly coil structure is proposed to adapt to the cylindrical symmetric hull of the autonomous underwater vehicles (AUVs). The unipolar and bipolar curly coils are optimised to minimise the weight of the receiver with the same output power. It is revealed that the bipolar curly coil structure has a heavier receiver than the unipolar curly coil structure. However, the electromagnetic field radiation in the AUV of the bipolar curly coil structure is much smaller than that of the unipolar curly coil structure, which means that the bipolar curly coil structure has a smaller influence on the electronics components in the AUV. Therefore, the bipolar curly coil is adopted for the prototype. The series−series (SS) and double‐sided inductor−capacitor−capacitor (LCC−LCC) compensation topologies for the bipolar curly coil structure are also investigated. A prototype was built and the experimental results showed that distorted coil currents are generated in the SS compensation topology, while the LCC−LCC compensation has a nearly sinusoidal coil current. The efficiencies of the SS and LCC−LCC compensation topologies are approximately the same, at ∼95%, which indicates that the proposed curly coil structure is applicable.
Optimal expansion planning of active distribution system considering coordinated bidding of downward active microgrids and demand response providers
Authors: Qaeini Saeed , Setayesh Nazar Mehrdad , Yousefian Morteza , Heidari Alireza , Shafie‐khah Miadreza , Catalão João P.S.
Published: February 2019

This paper addresses a framework for expansion planning of an active distribution network (ADS) that supplies its downward active microgrids (AMGs) and it participates in the upward wholesale market to sell its surplus electricity. The proposed novel model considers the impact of coordinated and uncoordinated bidding of AMGs and demand response providers (DRPs) on the optimal expansion planning. The problem has six sources of uncertainty: upward electricity market prices, AMGs location and time of installation, AMGs power generation/consumption, ADS intermittent power generations, DRP biddings, and the ADS system contingencies. The model uses the conditional value at risk (CVaR) criterion in order to handle the trading risks of ADS with the wholesale market. The proposed formulation integrates the deterministic and stochastic parameters of the risk‐based expansion planning of ADS that is rare in the literature on this field. The introduced method uses a four‐stage optimisation algorithm that uses genetic algorithm, CPLEX and DICOPT solvers. The proposed method is applied to the 18‐bus and 33‐bus test systems to assess the proposed algorithm. The proposed method reduces the aggregated expansion planning costs for the 18‐bus and 33‐bus system about 44.04% and 11.82% with respect to the uncoordinated bidding of AMGs/DRPs costs, respectively.
Design of an optical temperature transmitter for inflammable industry
Authors: Mandal Nirupama , Mondal Bikas , Sarkar Rajan
Published: February 2019

Measurement and transmission of temperature in industries are generally done by different conventional sensors like RTD, thermocouple, thermistor etc. that involve many limitations like high cost, temperature compensation and suffers from non‐linearity problems. Hence, a temperature sensing unit using AD590 temperature sensor is developed which is low cost, does not require any temperature compensation and exhibit linear characteristic. Furthermore, the signal transmission through electrical communication system is not acceptable through hazardous and inflammable areas and, therefore, optical transmission is being more acceptable as the signal does not alter due to electromagnetic interference and is free from explosions due to electric spark. So an optical communication technique has been proposed based on MZI. The proposed transmitter has been analysed theoretically, and the equations has been derived. The experiment has been performed on the fabricated prototype unit. The experimental and simulation results are presented in the paper which shows linear characteristic of the unit with very good repeatability and follows the theoretical equations.
Consequences of planetary migration on the minor bodies of the early solar system
Authors: Pirani S. , Johansen A. , Bitsch B. , Mustill A. J. , Turrini D.
Published: February 2019

Pebble accretion is an efficient mechanism that is able to build up the core of the giant planets within the lifetime of the protoplanetary disc gas-phase. The core grows via this process until the protoplanet reaches its pebble isolation mass and starts to accrete gas. During the growth, the protoplanet undergoes a rapid, large-scale, inward migration due to the interactions with the gaseous protoplanetary disc. In this work, we have investigated how this early migration would have affected the minor body populations in our solar system. In particular, we focus on the Jupiter Trojan asteroids (bodies in the coorbital resonance 1:1 with Jupiter, librating around the L4and L5Lagrangian points called, respectively, the leading and the trailing swarm) and the Hilda asteroids. We characterised their orbital parameter distributions after the disc dispersal and their formation location and compare them to the same populations produced in a classical in situ growth model. We find that a massive and eccentric Hilda group is captured during the migration from a region between 5 and 8 au and subsequently depleted during the late instability of the giant planets. Our simulations also show that inward migration of the giant planets always produces a Jupiter Trojans’ leading swarm more populated than the trailing one, with a ratio comparable to the current observed Trojan asymmetry ratio. The in situ formation of Jupiter, on the other hand, produces symmetric swarms. The reason for the asymmetry is the relative drift between the migrating planet and the particles in the coorbital resonance. The capture happens during the growth of Jupiter’s core and Trojan asteroids are afterwards carried along during the giant planet’s migration to their final orbits. The asymmetry and eccentricity of the captured Trojans correspond well to observations, but their inclinations are near zero and their total mass is three to four orders of magnitude higher than the current population. Future modelling will be needed to understand whether the dynamical evolution of the Trojans over billions of years will raise the inclinations and deplete the masses to observed values.
Tidal heating and the habitability of the TRAPPIST-1 exoplanets
Authors: Dobos Vera , Barr Amy C. , Kiss László L.
Published: February 2019

Context. New estimates of the masses and radii of the seven planets orbiting the ultracool M-dwarf TRAPPIST-1 star permit improved modelling of their compositions, heating by tidal dissipation, and removal of tidal heat by solid-state convection.

Aims. Here we compute the heat flux due to insolation and tidal heating for the inner four planets.

Methods. We apply a Maxwell viscoelastic rheology to compute the tidal response of the planets using the volume-weighted average of the viscosities and rigidities of the metal, rock, high-pressure ice, and liquid water/ice I layers.

Results. We show that TRAPPIST-1d and e can avoid entering a runaway greenhouse state. Planet e is the most likely to support a habitable environment, with Earth-like surface temperatures and possibly liquid water oceans. Planet d also avoids a runaway greenhouse, if its surface reflectance is at least as high as that of the Earth. Planets b and c, closer to the star, have heat fluxes high enough to trigger a runaway greenhouse and to support volcanism on the surfaces of their rock layers, rendering them too warm for life. Planets f, g, and h are too far from the star to experience significant tidal heating, and likely have solid ice surfaces with possible subsurface liquid water oceans.
A Jovian planet in an eccentric 11.5 day orbit around HD 1397 discovered by TESS
Authors: Nielsen L. D. , Bouchy F. , Turner O. , Giles H. , Mascareño A. Suárez , Lovis C. , Marmier M. , Pepe F. , Ségransan D. , Udry S. , Otegi J. F. , Ottoni G. , Stalport M. , Ricker G. , Vanderspek R. , Latham D. W. , Seager S. , Winn J. N. , Jenkins J. M. , Kane S. R. , Wittenmyer R. A. , Bowler B. , Crossfield I. , Horner J. , Kielkopf J. , Morton T. , Plavchan P. , Tinney C. G. , Zhang Hui , Wright D. J. , Mengel M. W. , Clark J. T. , Okumura J. , Addison B. , Caldwell D. A. , Cartwright S. M. , Collins K. A. , Francis J. , Guerrero N. , Huang C. X. , Matthews E. C. , Pepper J. , Rose M. , Villaseñor J. , Wohler B. , Stassun K. , Howell S. , Ciardi D. , Gonzales E. , Matson R. , Beichman C. , Schlieder J.
Published: February 2019

The Transiting Exoplanet Survey Satellite TESS has begun a new age of exoplanet discoveries around bright host stars. We present the discovery of HD 1397b (TOI-120.01), a giant planet in an 11.54-day eccentric orbit around a bright (V= 7.9) G-type subgiant. We estimate both host star and planetary parameters consistently usingEXOFASTv2based on TESS time-series photometry of transits and radial velocity measurements with CORALIE and MINERVA-Australis. We also present high angular resolution imaging with NaCo to rule out any nearby eclipsing binaries. We find that HD 1397b is a Jovian planet, with a mass of 0.415 ± 0.020MJand a radius of 1.026 ± 0.026RJ. Characterising giant planets in short-period eccentric orbits, such as HD 1397b, is important for understanding and testing theories for the formation and migration of giant planets as well as planet-star interactions.
Hot Exoplanet Atmospheres Resolved with Transit Spectroscopy (HEARTS)
Authors: Seidel J. V. , Ehrenreich D. , Wyttenbach A. , Allart R. , Lendl M. , Pino L. , Bourrier V. , Cegla H. M. , Lovis C. , Barrado D. , Bayliss D. , Astudillo-Defru N. , Deline A. , Fisher C. , Heng K. , Joseph R. , Lavie B. , Melo C. , Pepe F. , Ségransan D. , Udry S.
Published: February 2019

High-resolution optical spectroscopy is a powerful tool to characterise exoplanetary atmospheres from the ground. The sodium D lines, with their large cross sections, are especially suited to studying the upper layers of atmospheres in this context. We report on the results from Hot Exoplanet Atmosphere Resolved with Transit Spectroscopy survey (HEARTS), a spectroscopic survey of exoplanet atmospheres, performing a comparative study of hot gas giants to determine the effects of stellar irradiation. In this second installation of the series, we highlight the detection of neutral sodium on the ultra-hot giant WASP-76b. We observed three transits of the planet using the High-Accuracy Radial-velocity Planet Searcher (HARPS) high-resolution spectrograph at the European Southern Observatory (ESO) 3.6 m telescope and collected 175 spectra of WASP-76. We repeatedly detect the absorption signature of neutral sodium in the planet atmosphere (0.371 ± 0.034%; 10.75σ in a 0.75 Å passband). The sodium lines have a Gaussian profile with full width at half maximum (FWHM) of 27.6 ± 2.8 km s−1. This is significantly broader than the line spread function of HARPS (2.7 km s−1). We surmise that the observed broadening could trace the super-rotation in the upper atmosphere of this ultra-hot gas giant.
Reduced chemical scheme for modelling warm to hot hydrogen-dominated atmospheres
Authors: Venot O. , Bounaceur R. , Dobrijevic M. , Hébrard E. , Cavalié T. , Tremblin P. , Drummond B. , Charnay B.
Published: February 2019

Context. Three-dimensional models that account for chemistry are useful tools to predict the chemical composition of (exo)planet and brown dwarf atmospheres and interpret observations of future telescopes, such as James Webb Space Telescope (JWST) and Atmospheric Remote-sensing Infrared Exoplanet Large-survey (ARIEL). Recent Juno observations of the NH3 tropospheric distribution in Jupiter also indicate that 3D chemical modelling may be necessary to constrain the deep composition of the giant planets of the solar system. However, due to the high computational cost of chemistry calculations, 3D chemical modelling has so far been limited.

Aims. Our goal is to develop a reduced chemical scheme from the full chemical scheme of Venot et al. 2012 (A&A, 546, A43) able to reproduce accurately the vertical profiles of the observable species (H2O, CH4, CO, CO2, NH3, and HCN). This reduced scheme should have a size compatible with three-dimensional models and be usable across a large parameter space (e.g. temperature, pressure, elemental abundance). The absence of C2H2 from our reduced chemical scheme prevents its use to study hot C-rich atmospheres.

Methods. We used a mechanism-processing utility program designed for use with Chemkin-Pro to reduce a full detailed mechanism. The ANSYS© Chemkin-Pro Reaction Workbench allows the reduction of a reaction mechanism for a given list of target species and a specified level of accuracy. We took a warm giant exoplanet with solar abundances, GJ 436b, as a template to perform the scheme reduction. To assess the validity of our reduced scheme, we took the uncertainties on the reaction rates into account in Monte Carlo runs with the full scheme, and compared the resulting vertical profiles with the reduced scheme. We explored the range of validity of the reduced scheme even further by applying our new reduced scheme to GJ 436b’s atmosphere with different elemental abundances, to three other exoplanet atmospheres (GJ 1214b, HD 209458b, HD 189733b), a brown dwarf atmosphere (SD 1110), and to the troposphere of two giant planets of the solar system (Uranus and Neptune).

Results. For all cases except one, the abundances predicted by the reduced scheme remain within the error bars of the model with the full scheme. Expectedly, we found important differences that cannot be neglected only for the C-rich hot atmosphere. The reduced chemical scheme allows more rapid runs than the full scheme from which it is derived (~30× faster).

Conclusions. We have developed a reduced scheme containing 30 species and 181 reversible reactions. This scheme has a large range of validity and can be used to study all kinds of warm atmospheres, except hot C-rich ones that contain a high amount of C2H2. It can be used in 1D models, for fast computations, but also in 3D models for hot giant (exo)planet and brown dwarf atmospheres.
Detection of highly excited OH towards AGB stars
Authors: Khouri T. , Velilla-Prieto L. , De Beck E. , Vlemmings W. H. T. , Olofsson H. , Lankhaar B. , Black J. H. , Baudry A.
Published: February 2019

Aims. We characterise the gas in the extended atmospheres of the oxygen-rich asymptotic giant branch (AGB) stars W Hya and R Dor using high angular resolution ALMA observations.

Methods. We report the detection and investigate the properties of high-excitation Λ-doubling line emission of hydroxyl (OH).

Results. The OH lines are produced very close to the central stars and seem optically thin and with no maser effect. We analyse the molecular excitation using a population diagram and find rotational temperatures of ∼2500 K and column densities of ∼1019 cm−2 for both sources. For W Hya, we observe emission from vibrationally excited H2O arising from the same region as the OH emission. Moreover, CO v = 1, J = 3 − 2 emission also shows a brightness peak in the same region. Considering optically thin emission and the rotational temperature derived for OH, we find a CO column density ∼15 times higher than that of OH, within an area of (92 × 84) mas2 centred on the OH emission peak. These results should be considered tentative because of the simple methods employed. The observed OH line frequencies differ significantly from the predicted transition frequencies in the literature, and provide the possibility of using OH lines observed in AGB stars to improve the accuracy of the Hamiltonian used for the OH molecule. We predict stronger OH Λ-doubling lines at millimetre wavelengths than those we detected. These lines will be a good probe of shocked gas in the extended atmosphere and are possibly even suitable as probes of the magnetic field in the atmospheres of close-by AGB stars through the Zeeman effect.
Daylight Performances of Atrium Buildings for Different Roof Configuration Under Malaysia Sky Conditions
Authors: Yunus Julitta , Sh Ahmad Sabarinah , Zain-Ahmed Azni
Published: February 2019

The research endeavours to fill the identified gap in the field’s knowledge on daylighting in atriums, specifically under tropical sky conditions. The atrium’s form, roof configurations, building orientation, roof transmittance, internal surfaces reflectivity, and grazing areas are the key elements in the daylighting design of atrium buildings. Daylight availability in an atrium has been researched extensively using different techniques and models. This paper presents substantial findings from a virtual simulation exploration. Four models were used to perform the daylighting performance analyses involving field experiments and computer simulations (IESRadiance). The models used different roof fenestration designs and structural truss systems (flat, pitched, pyramidal-gridded and saw-tooth roofs) simulated for substantial virtual verification and investigation. The Daylight Factor/Daylight Ratio (DF/DR) on horizontal surfaces under different types of sky conditions at different times of day and different days over a period of one year were obtained. The illuminance levels were quantified for the unique circumstances of intermediate sky conditions. They show a generally linear relationship and a good degree of correlation with the overall reduction of daylight levels in the atrium. Internal roof obstructions created a relatively constant attenuation of daylight compared with the clear unobstructed roof for the four structured roofs. The discrepancy of light distribution was increased if measured between the unobstructed atrium well with complex configurations. This work has paved the way for more design strategies using complicated atrium roof fenestration constructions to be analysed with accuracy while combining aesthetics with energy efficiency.
Factors Influencing the Implementation of Technologies Behind Industry 4.0 in the Malaysian Construction Industry
Authors: Aripin Irrma Diana Mohd. , Zawawi Emma Marinie Ahmad , Ismail Zulhabri
Published: February 2019

Industry 4.0 is a concept which include Big Data and Analytics, Autonomous Robot, Simulation, System Integration, Internet of Things, Cyber Physical System, Cloud Computing, Additive Manufacturing and Augmented Reality. The makeover, not only completely change the way on how physical structures are designed, developed and preserved, but also how they are used in the future with applications of avant-garde technology. However there is a tendency that construction companies may be hesitant to invest in them. Industry 4.0 aims to motivate construction companies to adopt new technologies. Therefore, this paper aims to review on literature in identifying technologies that are used in line with Industry 4.0 as well as investigate the potential barriers faced and factors which influence the Industry 4.0 technologies implementation in the Malaysian construction industry. Relevant academic materials were reviewed thus the purpose of this paper is to present a literature review and critical analysis of the implementation of technologies behind Industry 4.0. Based on the results of the analysis, applications and uses, benefits, barriers and future needs are discussed. The results also reveal that the acceptance can help improves the image of the industry.
Green Cleaning: A Study on Benefits for Malaysian School Building
Authors: Ramli Nur Aqlima , Zawawi Emma Marinie , Muhamad Ariff Nor Rima , Kadir Siti Solehah , Zainol Nurul Nadiah
Published: February 2019

Cleaning is one of the important activities during the operation and maintenance stage to any type of core business. Schools nowadays are looking seriously at the cleaning aspect as they realize the availability of health and environmentally friendly facilities that encourage academic performance and staff welfare. These concerns are due to the conventional cleaning practices and products used to keep the school clean. The cleaning contractors are responsible to understand that chemicals with high levels of volatile organic compound (VOCs) emissions and other carcinogens plus dust from poorly filtered vacuums can have a negative impact on the health of students, staff and janitors. Thus, it is a good time for the building managers to make a move to green cleaning practice in school, as a rising number of green cleaning products that are much more effective are available. This study was hence conducted to identify the critical benefits that can be gained through the implementation of green cleaning practice in Malaysian school. Twelve benefits were identified from the literature, and a questionnaire survey that involved green cleaning experts was carried out. Frequency analysis and Importance Index calculation were performed to rank the benefits. The result indicates that “improve indoor air quality (IAQ)” and “provide a safe and healthy environment to occupants and janitors” are the most important benefits of green cleaning practice during operation and maintenance stages in Malaysian school. The findings of this study can provide a significant contribution to the built environment industry. By knowing the benefits that can be gained through green cleaning implementation, efforts can be carried out to explore measures that can be taken to implement the green cleaning practice in Malaysian school or other types of building.
The Role of Belt Wall in Minimizing The Response Due To Wind Load
Authors: Samat Roslida Abd. , Mohamed Ali Nasly , Kadir Marsono Abdul , Fadzil Abu Bakar
Published: February 2019

Outrigger is one of the tall building structural systems that are used to reduce the building responses due to the wind. Outrigger is a stiff beam that connects the core wall to exterior columns and this enables the vertical shear to be transferred from the core to the external columns, thereby forcing the perimeter columns to participate in carrying the overturning moment due to the wind. Belt wall is often added to a building with outrigger system to further reduce the displacement and acceleration of a tall building having an outrigger system. However, it is not known how effective the belt wall is in further reducing the building responses. Thus, 64 story reinforced concrete buildings are studied in order to determine how the belt wall improves the building responses due to the wind. Buildings with an outrigger system and buildings with a combination of the outrigger and belt wall system are analysed by a structural engineering software in order to determine the natural frequencies and eigenvectors in the along-wind, across-wind and torsional direction. The along-wind responses are determined by employing the procedures from the ASCE 7-16 while the across-wind responses of the buildings are calculated based on the procedures and wind tunnel data available in a database of aerodynamic load. Results from the analysis show that the belt wall reduces the along-wind and across-wind responses slightly. However, belt wall reduces the torsional acceleration of the buildings significantly, which otherwise cannot be reduced by the outrigger system.
Significant Factors Affecting Civil Engineering Project Performance
Authors: Ismail Wan Norizan Wan , Adnan Hamimah , Hassan Ahmad Arzlee , Mahat Noor Aisyah Asyikin , Baharuddin Har Einur Azrin
Published: February 2019

Civil engineering projects trigger the economic growth by providing infrastructure facilities and job opportunities as well as attracting the attention of foreign investments. Due to their significant contributions toward the nation growth, the performance of civil engineering projects has become the upmost concern by the government. Unfortunately, many civil engineering projects in Malaysia are dominantly associated with unsatisfactory performance in terms of cost, time and quality of the delivered products. Therefore, this paper aims to identify the underlying causes which lead to unsatisfactory performance by determining the factors affecting civil engineering projects. The objective of this paper is to identify the civil engineering project characteristics and the quality of Standard Form of Contract (SFoC) adopted and the contractual behaviour of key participants of civil engineering project which affecting the performance. Questionnaires survey were conducted to undertake the research. 124 feedbacks received out of 300 questionnaires distributed to the G7 contractors registered under Construction Industry Development Board (CIDB) and consultant engineer registered under Board of Engineers Malaysia (BEM). The data was statistically analysed using SPSS 21 and descriptive analysis was used for rank assessment of factors. It was found that the top three (3) most significant factors affecting civil engineering project performance are delay in making payment, environment uncertainty and the clarity of SFoC. These factors belong to three categories i.e the contractual behaviour of key participants, project characteristics and the quality of SFoC category. Thus, these categories are paramount to be put more concern on the performance of civil engineering projects in Malaysia.
Performance of Dredged Sediment as a Replacement for Fine Aggregates in Concrete Mixture: Case Study at Sungai Pekan, Pahang
Authors: Manap Norpadzlihatun , Govindasamy Gomathi , Mohamed Sulzakimin , Kasim Narimah , Meryam Shareh Musa Sharifah , Yamani Yahya Mohd
Published: February 2019

Dredging is essential to maintain suitable depth for shipping by removing dredged sediments from sea and river banks. It is also an important process to supply construction material. In Pahang, increasing flood cases is occurring due to increased sea and river bed level. Thus, dredging is needed to be performed in this location. In addition, the rapid growth of the construction industry requires a sustainable approach. The reuse of dredged sediments as construction material could be a sustainable approach. Therefore, this research aims to study the engineering properties of dredged sediments and to compare the strength of concrete made from dredged sediments with conventional concrete. The samples for this research obtained from the location of this study at Sungai Pekan. Laboratory testing was performed to determine the engineering properties of dredged sediments and compressive strength of concrete produced from the dredged sediments. The highest average compressive strength of the concrete cube produced from Sample 1 is 9.2 N/mm² for seven days and 11.9 N/mm² for 28 days curing period. Comparatively, Sample 3 has the lowest average compressive strength that is 2.1 N/mm² for seven days and 2.7 N/mm² for 28 days curing period. The strength that is required to be achieved is 14 N/mm² for curing seven days and 20 N/mm² for curing period of 28 days. In conclusion, the concrete cubes made from dredged sediment taken at the sampling area are unable to produce concrete that satisfies the minimum strength for the C20 concrete mix. Therefore, it can be concluded that there is the minimal potential use of dredged sediments taken from the location of this study for the production of concrete in the construction industry.
Application of Frequency Analysis on Peak River Discharge toward the Cumulative Floatable Litter Load at Log Boom Sungai Batu
Authors: Abdul Malik Nur Khaliesah , Jamil Nor Rohaizah , Abd Manaf Latifah , Rosli Mohd Hafiz , Ash’aari Zulfa Hanan , Mohd Yusof Fasihah
Published: February 2019

The accumulation of floatable litter in the river is mainly influenced by the increasing number of human population, rapid urbanization and development which indirectly lead to the changes of hydrological processes in river discharge, decreasing the water quality and aesthetical value of the river. The main objective of this paper is to determine the cumulative floatable litter load captured at the log boom during the extreme events by using the Gumbel distribution method for frequency analysis in river discharge of Sungai Batu. The annual maximum river discharge for a period of 35 years (1982 to 2016) was used in Gumbel distribution method to obtain the discharge for different return period (2, 5, 10, 25, 50, 100, and 200). The result shows that the estimated discharge (103.17 m³/s) can estimate the cumulative floatable litter load (53267.27 kg/day) at 50 years return period. The R2 value obtained from non – linear regression analysis is 0.9986 indicate that Gumbel distribution is suitable to predict the expected discharge of the river. This study is very crucial for the related agencies in highlighting this environmental issues for their future references which can be used as a guidelines during the decision making process in making better improvement.
Adopting the Zero Waste Concept for Eliminating C&D Waste in the Construction Industry
Authors: Liyanage K.L.A.K.T. , Waidyasekara K.G.A.S. , Mallawaarachchi H.
Published: February 2019

Construction industry is one of the key economic players in any region, where Construction and Demolition (C&D) waste generation occurs due to continuous construction and demolition activities. The C&D waste mainly comprises cement, timber, brick, concrete, aluminium, tile, steel, plastic, polythene, paper, and cardboard. Such wastes have led to several environmental, economic, and social issues over the past years. Therefore, C&D waste management is considered as a persuasive matter that needs to address, and hence, the “Zero Waste” concept has emerged as a solution to eliminate the C&D waste. Zero waste is the elimination of waste at the source and throughout the construction activity. Accordingly, implementation of the Zero waste concept in the construction industry helps to optimise the use of natural resources, reduce environmental issues and to promote sustainability. However, only limited studies are available on zero waste management in the construction industry, and hence the present study aims to investigate the adoption of zero waste concept to eliminate C&D waste in developing countries. The paper outcomes based on a comprehensive literature review and the significant findings of this research paper are the recognition of strategies, enablers, and barriers to adopting zero waste concept in the construction industry.
Strategy implementation process for better employees’ performance in construction companies
Authors: Zaidi Faza Ihsan , Ahmad Zawawi Emma Marinie , Mohd Nordin Rumaizah
Published: February 2019

Strategy implementation is known as the most tedious and challenging stage in strategic planning. Strategy implementation can influence the whole texture of a company, including its employees’ performance. Studies have shown that improper strategy implementation can lead to poor employees’ performance. However, there is still a lack of empirical evidence to prove this relationship. Strategy implementation process implemented differ between companies. It influences the employees’ commitment, retention and growth and hence performance. The aim of this research is to analyse the relationship between the strategy implementation process and employees’ performance in construction companies. Respondents were G7 contractors in Klang Valley, Selangor. Pearson correlation analysis was used to analyse the data and it is proven that the strategy implementation process influences the employees’ performance in construction companies. Based on the data correlation, construction companies which provide training for employees to carry out the strategic action plan able to gain positive employees’ performance. This research shows that the strategy implementation process does influence employees’ performances in construction companies especially toward employees’ retention and employees’ growth. Top management in the construction companies can use this research as a tool to conduct strategy implementation in their companies.