bluuebunny/crossref_metadata_2025 huggingface dataset:
Determination of arsenic in biological samples by slurry sampling hydride generation atomic fluorescence spectrometry usingin situdielectric barrier discharge trap
Authors: Liu Meitong , Liu Tengpeng , Liu Jixin , Mao Xuefei , Na Xing , Ding Lan , Chen Guoying , Qian Yongzhong
Published: January 2019

In this study, the slurry sampling hydride generation (SLS-HG) system was first coupled within situdielectric barrier discharge atomic fluorescence spectrometry (DBD-AFS) for arsenic analysis in biological samples based on the gas phase enrichment (GPE) principle.
ZIF-8 derived ZnO/Zn6Al2O9/Al2O3nanocomposite with excellent photocatalytic performance under simulated sunlight irradiation
Authors: Zhang Li , Liang Qingman , Yang Peng , Huang Yang , Liu Younian , Yang Haihua , Yan Jianhui
Published: January 2019

The ZIF-8 derived ZnO/Zn6Al2O9/Al2O3nanocomposite exhibits an unprecedented photocatalytic degradation activity toward MO of high concentration.
Graphene oxide/nanometal composite membranes for nanofiltration: synthesis, mass transport mechanism, and applications
Authors: Yang Kun , Huang Lin-jun , Wang Yan-xin , Du Ying-chen , Tang Jian-guo , Wang Yao , Cheng Meng-meng , Zhang Yang , Kipper Matt J. , Belfiore Laurence A. , Wickramasinghe S. Ranil
Published: January 2019

We reviewed the recent developments in graphene-based composite membranes and discussed their challenges in this paper.
In situ growth of CuS decorated graphene oxide-multiwalled carbon nanotubes for ultrasensitive H2O2 detection in alkaline solution
Authors: Jin Wei , Fu Yanqiu , Cai Weiquan
Published: January 2019

A novel hybrid nanomaterial composed of nanoparticles, nanotubes and nanosheets for electrochemical H2O2 detection.
Curvature-driven adsorption of cationic nanoparticles to phase boundaries in multicomponent lipid bilayers
Authors: Sheavly Jonathan K. , Pedersen Joel A. , Van Lehn Reid C.
Published: January 2019

Coarse-grained molecular dynamics simulations and free energy calculations reveal that cationic nanoparticles preferentially adsorb to regions of intrinsic negative curvature at phase boundaries in multicomponent lipid bilayers.
Stable, color-tunable 2D SCN-based perovskites: revealing the critical influence of an asymmetric pseudo-halide on constituent ions
Authors: Li Chia-Hsin , Tsai Chang-Che , Liao Ming-Yun , Su Yu-An , Lin Shiang-Tai , Chueh Chu-Chen
Published: January 2019

It is revealed that the linear SCN− anion dictates critical restriction on the constituent ions of its derived 2D (PbX4(SCN)2) framework.
Bionicomposites
Authors: Pugno Nicola M. , Valentini Luca
Published: January 2019

Incorporating nanomaterials in living systems could force the latter to produce “bionicomposites”.
Au decoration of a graphene microchannel for self-activated chemoresistive flexible gas sensors with substantially enhanced response to hydrogen
Authors: Kim Yeonhoo , Choi Yong Seok , Park Seo Yun , Kim Taehoon , Hong Seung-Pyo , Lee Tae Hyung , Moon Cheon Woo , Lee Jong-Heun , Lee Donghwa , Hong Byung Hee , Jang Ho Won
Published: January 2019

Unprecedented hydrogen detection at room temperature by Au nanoclusters supported on a self-activated graphene microchannel is demonstrated.
Metal-dependent inhibition of amyloid fibril formation: synergistic effects of cobalt–tannic acid networks
Authors: Zhang Wenjie , Christofferson Andrew J. , Besford Quinn A. , Richardson Joseph J. , Guo Junling , Ju Yi , Kempe Kristian , Yarovsky Irene , Caruso Frank
Published: January 2019

Cobalt–tannic acid-coated gold nanoparticles are found to better inhibit amyloid fibril formation than other metal-based tannic acid-coated particles.
DNA dumbbell tiles with uneven widths for 2D arrays
Authors: Ali Mashooq , Afshan Noshin , Jiang Chuan , Xiao Shou-Jun
Published: January 2019

DNA dumbbell tiles of AO(E) and BO(E), with stem spans of 11 and 16 bp twisting two head loop motifs of each tile into parallel and antiparallel conformations respectively, were constructed to grow planar nanoribbon arrays and nanotubes as well.
Nickel-catalyzed regioselective C–H oxygenation: new routes for versatile C–O bond formation
Authors: Li Ze-lin , Sun Kang-kang , Cai Chun
Published: January 2019

Nickel-catalyzed regioselective C–H oxygenation reactions of chelating arenes using iodobenzene diacetate, alcohols, and benzoic acids respectively as attacking reagents have been developed for the first time.
Photostability and photocatalytic degradation of ionic liquids in water under solar light
Authors: Bedia Jorge , Rodriguez Juan José , Moreno Daniel , Palomar José , Belver Carolina
Published: January 2019

The aim of this work is to study, (i) the photostability of different imidazolium and pyridinium ionic liquids (ILs) in water under solar light; and (ii) the photocatalytic degradation of those ILs in water with TiO2 under solar light.
Electropolymerization of thienyl tethered comonomers and application towards the electrocatalytic reduction of nitrobenzene
Authors: Raheem Abbasriyaludeen Abdul , Gopi Sivalingam , Kathiresan Murugavel , Praveen Chandrasekar
Published: January 2019

The synthesis of different π-spacered thiophene comonomers via Suzuki cross-coupling in good synthetic yields was accomplished.
Effect of lignocellulose-derived weak acids on butanol production byClostridium acetobutylicumunder different pH adjustment conditions
Authors: Wang Jianhui , Yang Hongyan , Qi Gaoxaing , Liu Xuecheng , Gao Xu , Shen Yu
Published: January 2019

The effects of formic acid, acetic acid and levulinic acid on acetone–butanol–ethanol (ABE) fermentation under different pH adjustment conditions were investigated usingClostridium acetobutylicumas the fermentation strain.
Dynamic impact response of lithium-ion batteries, constitutive properties and failure model
Authors: Kermani Golriz , Sahraei Elham
Published: January 2019

Dynamic response and failure of pouch and elliptical cells under impact loading.
Applying rhamnolipid to enhance hydrolysis and acidogenesis of waste activated sludge: retarded methanogenic community evolution and methane production
Authors: Li Jiaqi , Liu Wenzong , Cai Weiwei , Wang Bo , Ajibade Fidelis Odedishemi , Zhang Zhaojing , Tian Xiadi , Wang Aijie
Published: January 2019

Recently, bio-surfactants, like rhamnolipid (RL), have been used as efficient pre-treatments to enhance the accumulation of short-chain fatty acids (SCFAs) from waste activated sludge (WAS).
A solid-state chemical method for synthesizing MgO nanoparticles with superior adsorption properties
Authors: Zhang Hongyu , Hu Jindou , Xie Jing , Wang Shiqiang , Cao Yali
Published: January 2019

As a traditional and effective adsorbent, MgO is a low-cost, eco-friendly, nontoxic, and economical material for wastewater treatment.
Investigation of pH-responsive block glycopolymers with different structures for the delivery of doxorubicin
Authors: Abdalla Ibrahim , Xu Jiaming , Wang Danyue , Tong Han , Sun Bin , Ding Bin , Jiang Xiaoze , Zhu Meifang
Published: January 2019

Synthesized a pH-responsive block glycopolymers micelles, for the DOX loading and release behavior enhancing the design of drug delivery systems.
Lipid-independent control of endothelial and neuronal TRPC3 channels by light
Authors: Tiapko Oleksandra , Shrestha Niroj , Lindinger Sonja , Guedes de la Cruz Gema , Graziani Annarita , Klec Christiane , Butorac Carmen , Graier Wolfgang. F. , Kubista Helmut , Freichel Marc , Birnbaumer Lutz , Romanin Christoph , Glasnov Toma , Groschner Klaus
Published: January 2019

A new photochromic ligand enables high precision control over native TRPC channels.
Thermodynamic modelling of acidic collagenous solutions: from free energy contributions to phase diagrams
Authors: Khadem Sayyed Ahmad , Rey Alejandro D.
Published: January 2019

Tropocollagen is considered one of the main precursors in the fabrication of collagen-based biomaterials.
Hierarchically structured rugae-like RuP3–CoP arrays as robust catalysts synergistically promoting hydrogen generation
Authors: Guo Jingya , Wu Chongbei , Zhang Jifang , Yan Puxuan , Tian Jianniao , Shen Xingcan , Isimjan Tayirjan Taylor , Yang Xiulin
Published: January 2019

Designing a highly active and stable catalyst for NaBH4 hydrolysis is a key step towards overcoming the challenges of hydrogen storage.
Plasma-functionalized carbon-layered separators for improved performance of lithium sulfur batteries
Authors: Ahn Jee Hun , Shin Hyun-Jin , Abbas Saleem , Lee Kwan-Young , Ha Heung Yong
Published: January 2019

Novel plasma-functionalized carbon-coated separators improve the overall performance of Li–S batteries.
Cobalt nanoparticle-embedded nitrogen-doped carbon/carbon nanotube frameworks derived from a metal–organic framework for tri-functional ORR, OER and HER electrocatalysis
Authors: Guo Hele , Feng Qichun , Zhu Jixin , Xu Jingsan , Li Qianqian , Liu Siliang , Xu Kaiwen , Zhang Chao , Liu Tianxi
Published: January 2019

A Co@N-CNTF electrocatalyst derived from a metal–organic framework exhibits high catalytic activity in the ORR, OER and HER.
Doping and phase segregation in Mn2+- and Co2+-doped lead halide perovskites from133Cs and1H NMR relaxation enhancement
Authors: Kubicki Dominik J. , Prochowicz Daniel , Pinon Arthur , Stevanato Gabriele , Hofstetter Albert , Zakeeruddin Shaik M. , Grätzel Michael , Emsley Lyndon
Published: January 2019

Lead halide perovskites belong to a broad class of compounds with appealing optoelectronic and photovoltaic properties.
Polyoxometalate-assisted formation of CoSe/MoSe2 heterostructures with enhanced oxygen evolution activity
Authors: Yuan Menglei , Dipazir Sobia , Wang Meng , Sun Yu , Gao Denglei , Bai Yiling , Zhang Min , Lu Peilong , He Hongyan , Zhu Xiangyang , Li Shuwei , Liu Zhanjun , Luo Zhaopeng , Zhang Guangjin
Published: January 2019

The heterostructured CoSe/MoSe2 hybrids was fabricated by a non-metal induced growth method for efficient oxygen evolution reaction (OER).
Engineering of a bioluminescent probe for imaging nitroxyl in live cells and mice
Authors: Li Jun-Bin , Wang Qianqian , Liu Hong-Wen , Yin Xia , Hu Xiao-Xiao , Yuan Lin , Zhang Xiao-Bing
Published: January 2019

A turn-on bioluminescent probe (BP-HNO) that is free of autofluorescence for bioimaging nitroxyl in live cells and mice is reported for the first time.
The role of extracellular vesicles in cancer microenvironment and metastasis: myths and challenges
Authors: Lucien Fabrice , Leong Hon S.
Published: January 2019

The concept of vesicles or cell debris released by cancer cells to promote metastasis is not new, but the mechanisms used to currently ascribe their impact in metastasis are of intense debate. A significant increase in reports describing the role of cancer-derived EVs in cancer metastasis has been followed by a growing amount of uncertainty behind these claims. This review will delve into the role of EVs in promoting cancer metastasis by relying on a balanced perspective that looks at challenges faced previously by extracellular vesicle biologists, current technical limitations in the field, and overlooked physiologic mechanisms that may play a confounding role. This review will also discuss how certain experimental approaches are misleading which ultimately lead to overly optimistic mechanisms that have minimally contributed to the pathophysiology of metastasis.
Structural mass spectrometry comes of age: new insight into protein structure, function and interactions
Authors: Allison Timothy M. , Bechara Cherine
Published: January 2019

Mass spectrometry (MS) provides an impressive array of information about the structure, function and interactions of proteins. In recent years, many new developments have been in the field of native MS and these exemplify a new coming of age of this field. In this mini review, we connect the latest methodological and instrumental developments in native MS to the new insights these have enabled. We highlight the prominence of an increasingly common strategy of using hybrid approaches, where multiple MS-based techniques are used in combination, and integrative approaches, where MS is used alongside other techniques such as ion-mobility spectrometry. We also review how the emergence of a native top-down approach, which combines native MS with top-down proteomics into a single experiment, is the pièce de résistance of structural mass spectrometry's coming of age. Finally, we outline key developments that have enabled membrane protein native MS to shift from being extremely challenging to routine, and how this technique is uncovering inaccessible details of membrane protein–lipid interactions.
Mechanisms of antibiotics inhibiting bacterial RNA polymerase
Authors: Mosaei Hamed , Harbottle John
Published: January 2019

Transcription, the first phase of gene expression, is performed by the multi-subunit RNA polymerase (RNAP). Bacterial RNAP is a validated target for clinical antibiotics. Many natural and synthetic compounds are now known to target RNAP, inhibiting various stages of the transcription cycle. However, very few RNAP inhibitors are used clinically. A detailed knowledge of inhibitors and their mechanisms of action (MOA) is vital for the future development of efficacious antibiotics. Moreover, inhibitors of RNAP are often useful tools with which to dissect RNAP function. Here, we review the MOA of antimicrobial transcription inhibitors.
An updated structural classification of replicative DNA polymerases
Authors: Raia Pierre , Delarue Marc , Sauguet Ludovic
Published: January 2019

Replicative DNA polymerases are nano-machines essential to life, which have evolved the ability to copy the genome with high fidelity and high processivity. In contrast with cellular transcriptases and ribosome machines, which evolved by accretion of complexity from a conserved catalytic core, no replicative DNA polymerase is universally conserved. Strikingly, four different families of DNA polymerases have evolved to perform DNA replication in the three domains of life. In Bacteria, the genome is replicated by DNA polymerases belonging to the A- and C-families. In Eukarya, genomic DNA is copied mainly by three distinct replicative DNA polymerases, Polα, Polδ, and Polε, which all belong to the B-family. Matters are more complicated in Archaea, which contain an unusual D-family DNA polymerase (PolD) in addition to PolB, a B-family replicative DNA polymerase that is homologous to the eukaryotic ones. PolD is a heterodimeric DNA polymerase present in all Archaea discovered so far, except Crenarchaea. While PolD is an essential replicative DNA polymerase, it is often underrepresented in the literature when the diversity of DNA polymerases is discussed. Recent structural studies have shown that the structures of both polymerase and proofreading active sites of PolD differ from other structurally characterized DNA polymerases, thereby extending the repertoire of folds known to perform DNA replication. This review aims to provide an updated structural classification of all replicative DNAPs and discuss their evolutionary relationships, both regarding the DNA polymerase and proofreading active sites.
H2 influenza viruses: designing vaccines against future H2 pandemics
Authors: Reneer Z. Beau , Ross Ted M.
Published: January 2019

Influenza-related pathologies affect millions of people each year and the impact of influenza on the global economy and in our everyday lives has been well documented. Influenza viruses not only infect humans but also are zoonotic pathogens that infect various avian and mammalian species, which serve as viral reservoirs. While there are several strains of influenza currently circulating in animal species, H2 influenza viruses have a unique history and are of particular concern. The 1957 ‘Asian Flu’ pandemic was caused by H2N2 influenza viruses and circulated among humans from 1957 to 1968 before it was replaced by viruses of the H3N2 subtype. This review focuses on avian influenza viruses of the H2 subtype and the role these viruses play in human infections. H2 influenza viral infections in humans would present a unique challenge to medical and scientific researchers. Much of the world's population lacks any pre-existing immunity to the H2N2 viruses that circulated 50–60 years ago. If viruses of this subtype began circulating in the human population again, the majority of people alive today would have no immunity to H2 influenza viruses. Since H2N2 influenza viruses have effectively circulated in people in the past, there is a need for additional research to characterize currently circulating H2 influenza viruses. There is also a need to stockpile vaccines that are effective against both historical H2 laboratory isolates and H2 viruses currently circulating in birds to protect against a future pandemic.
Injection‐locked rotary travelling pulse in closed tunnel‐diode line for multiphase oscillation
Authors: Higashi M. , Sawai S. , Narahara K.
Published: January 2019

Injection‐locking properties of a rotary travelling pulse developed in a system of tunnel‐diode (TD) transmission lines are characterised for multiphase oscillation. The system includes a unique TD line loop coupled with evenly spaced straight TD lines. The oscillating voltage edges in straight lines are synchronised to organise the rotary pulse on the closed one. Based on the phase‐reduction theory, the authors determine where to connect an external oscillator for sufficient locking frequency range. Inherently, the travelling pulse can rotate on the loop in either clockwise or anti‐clockwise fashion. The rotation frequency slightly depends on the rotation direction by the finite fluctuation of device parameter values. By matching the frequency of the external oscillator with one of such frequencies, the rotation direction is specified as required. These injection‐locking properties are validated experimentally.
Design improvement of dual‐pole LSPM synchronous motor
Authors: Ghoroghchian Fakhrossadat , Damaki Aliabad Aliakbar , Amiri Ebrahim
Published: January 2019

This article presents a design improvement of the dual‐pole, two‐speed line start permanent magnet (LSPM) synchronous motor. For this purpose, the operational performance of the motor with dual‐pole structure is first compared with the conventional single‐pole motor to identify its performance limitations. Next, the structure of the dual‐pole rotor is modified accordingly to address the related limitations. The proposed, modified design reduces the number of PMs in the rotor structure and offers a better steady state and transient performance. The motor is analysed using 2D finite element analysis (FEA), and results are verified by experimental tests on the motor prototype.
Enhancing the stability of AHF
Authors: Vaidya Tushar , Chatterjee Kishore
Published: January 2019

Active harmonic filters (AHFs) have a problem of losing their stability when they are installed in a distribution network having power factor correction (PFC) capacitors. This study has made an effort to assess the stability margin of an AHF installed in a distribution network along with PFC capacitors. After establishing the underlying cause of instability, an attempt has been made in this study to propose a control algorithm, so that the problem of instability is overcome when these AHFs are made to operate in tandem with PFC capacitors. The effectiveness of the proposed control algorithm is established by carrying out detailed simulation studies of the system. A 30 kVA laboratory prototype of the AHF has been fabricated. Detailed experimental validations have been carried out utilising the aforesaid prototype to confirm the viability of the proposed scheme.
Mixed model‐based and signal‐based approach for open‐switches fault diagnostic in sensorless speed vector controlled induction motor drive using sliding mode observer
Authors: Maamouri Rebah , Trabelsi Mohamed , Boussak Mohamed , M'Sahli Faouzi
Published: January 2019

This study deals with a mixed model‐based and signal‐based approach for sensorless speed‐controlled induction motor drive (IM) and insulated‐gate bipolar transistors open‐switch fault diagnosis. In comparison to the classical sensored drive systems, this structure presents particular characteristics in post‐fault operation mode which can be taken into account for fault detection and identification process designing. Firstly, the fault effects analysis is achieved in the abc frame of the IM. Based on such analysis, a diagnostic algorithm, using the measured and estimated currents, is used to define the fault indices, which allow the detection of single open‐switch, multiple open‐switch and open‐phase faults. The sensorless control algorithm used for rotor speed estimation, as well as the fault diagnostic algorithm, are all based on a first‐order sliding mode observer. In addition to the simplicity and the fast fault detection, there are no‐additional sensors or extra‐hardware used by the proposed method. Experimental results, based on a dSPACE DS1104 controller board and a 3‐kW induction machine, are shown to validate the proposed strategy.
Simple digital algorithm for improved performance in a boost PFC converter operating in CCM
Authors: Nair Harish Sudhakaran , Narasamma Lakshmi
Published: January 2019

In power factor correction (PFC) converters, achieving both good steady‐state input current waveform and fast output dynamic response is a challenge. This is due to the effect of the double‐line frequency ripple present in the sensed output voltage signal which tends to distort the reference current applied to the current controller, thus leading to a distorted input current waveform. Low bandwidth (BW) voltage loop designs to reduce this input current distortion make the output dynamic response very sluggish. A digital control algorithm for the estimation of the average value of the sensed output voltage is proposed in this study to achieve low total harmonic distortion input current and fast dynamic response with a higher BW voltage loop. The proposed algorithm is computationally less intensive and requires no additional sensors or circuitry. The effectiveness of the proposed control algorithm is validated through simulation and experimental tests on a 300 W boost PFC converter prototype operating in continuous conduction mode.
Modulation and control method for double‐switch buck–boost converter
Authors: You Jiang , Fan Weiyan , Ghasemi Negareh , Vilathgamuwa Mahinda
Published: January 2019

Double‐switch buck–boost converter is a distinctly suitable candidate for the front‐end converter in two‐stage power converter systems that can perform step‐up/down power conversion. Several modulation schemes, such as synchronisation modulation (SM), interleaved modulation (IM) and combined control strategy have been proposed for this converter, and these methods yield notable advantages in different aspects, such as amplitude of inductor ripple current, conversion efficiency, power density and so on. However, the requirements of the converter are not only limited in the aforementioned metrics, but the related complexity of control system design, implementation and control performance sometimes also play important roles in industry applications. A novel modulation scheme is proposed in this study to obtain a balanced performance in terms of ripple/average current of the inductor, and to operate along with a model based control system and finally, the conversion efficiency is compared to the SM and IM modulation methods. Experimental results are presented to demonstrate the effectiveness of the proposed modulation method.
Optimal multi‐configuration and allocation of SVR, capacitor, centralised wind farm, and energy storage system: a multi‐objective approach in a real distribution network
Authors: Ahmadi Mikaeel , Lotfy Mohamed Elsayed , Danish Mir Sayed Shah , Ryuto Shigenobu , Yona Atsushi , Senjyu Tomonobu
Published: January 2019

Extension of renewable energies in power system planning and operation especially distribution networks is not limited to power sustainability. It also encompasses many significant contributions such as eliminating electricity shortages by diversifying energy supply, improving reliability with power quality, reducing greenhouse gas emissions, and providing energy independence, which is the most crucial aspect for both developed and developing countries power sector. The extraction of such benefits in the best manner can be achieved by considering storage and control devices, aiding well‐configured electricity networks through competitive optimisation techniques. By taking such points into consideration, optimal multi‐configuration and allocation of step‐voltage regulators (SVRs), capacitor banks, and energy storage system along with centralised wind‐power generation integrating to distribution network are investigated and applied, using a novel and Pareto based epsilon multi‐objective genetic algorithm. The proposed methodology is applied to an extensive and real 162‐bus distribution network in Kabul city to validate its sturdiness. The simulations are performed in MATLAB® environment with six configuration scenarios to compare the effect of multiple arrangements in the distribution network, and to discover the best configuration fulfilling the optimisation criteria with the objective functions being as power loss, voltage deviation, and violation cost.
Artificial intelligence solution to extract the dielectric properties of materials at sub‐THz frequencies
Authors: Güneşer Muhammet Tahir
Published: January 2019

Material characterisation plays a crucial role in many applications such as security, military, communication, bioengineering, medical treatment, food industry and material processing. Since it is useful to identify other properties of materials often tied to other useful parameters, such as stress–strain relation, bio content, moisture content, materials density and so on, the dielectric properties of materials should be achieved with high accuracy using appropriate measurement techniques and extraction techniques. There are many measurement methods to determine the dielectric properties of materials, which depend on parameters such as frequency range, material phase and temperature. In this study, the measurement methods and extraction techniques have been discussed, and alternative ways have been presented with experimental and simulation results. Furthermore, a new numerical extraction technique has been performed to achieve the dielectric properties of materials.
Design and development of travelling‐wave‐frequency‐based transmission line fault locator using TMS320 DSP
Authors: Arkan Müslüm , Akmaz Düzgün , Mamiş Mehmet S. , Tağluk Mehmet Emin
Published: January 2019

The authors use a TMS320 digital signal processor (TMS320‐DSP) to determine fault instants and estimate their location in real time in a laboratory environment. The fault instant is determined via examining the instantaneous differential changes in the line currents. After the fault is detected, the fault location is determined by processing the time‐domain transient current waves. First, the travelling‐wave frequency is determined by application of the fast Fourier transform to the positive‐sequence‐component line current after the fault, and subsequently, the fault location is estimated by utilising this frequency. The alternative transients programme (ATP)–electromagnetic transient programme is used to simulate the line currents and create short‐circuit fault conditions. Furthermore, LabVIEW software and a National Instruments data acquisition board are used to transform the line currents obtained through the ATP programme into analogue signals. The TMS320‐DSP determines the fault in real time and estimates the fault location using the completed software and analogue input signals. Their results indicate that the prototype device designed with the use of the TMS320‐DSP is suitable for real‐time fault detection.
Robust control of HIV infection by antiretroviral therapy: a super‐twisting sliding mode control approach
Authors: Bera Manas Kumar , Kumar Pintu , Biswas Raj Kumar
Published: January 2019

Acquired immune deficiency syndrome is an epidemic infectious disease which is caused by the human immunodeficiency virus (HIV) and that has proliferated across worldwide. It has been a matter of concern for the scientific community to develop an antiretroviral therapy, which will prompt a rapid decline in viral abundance. With this motivation, this study proposes the design of a robust super twisting sliding mode controller based on output information for an uncertain HIV infection model. The control objective is to decrease the concentration of infected CD4+ T cells to a specified level by drug administration using only the output information of the uncertain HIV infection model which is total CD4+ T cell concentration. The robust output‐feedback controller has been developed in combination with a robust exact differentiator, functioning as an observer. The reported analysis demonstrates that the approach proposed here is capable of ensuring robust performance under several operating conditions, measurement and modelling error, parametric uncertainties and external disturbances and the simulation results prove the proficiency of the controller proposed.
System design for Nanjing HVDC flexible transmission project
Authors: Fei Mei , Li Wang , Shengsen Zha , Jianyong Zheng
Published: January 2019

In order to solve the problem of power supply shortage in certain region of Nanjing city, a high‐voltage direct current (HVDC) flexible transmission project needs to be constructed. It could be the first project with ±380 kV DC and real bipolar connection in the world. Two new converter stations will be built with 1500 MW transmission capacity. The system design scheme has been proposed including the main connection mode of converter stations, the operation mode, the control strategy, parameters design for main circuit and determination of converter station's power operation range. This technical solution can provide complete design method for future HVDC flexible transmission project, which is of great significance to the development and engineering application of the HVDC flexible technology in China.
Research of controlled switching strategy to restrain inrush current during the energisation of converter transformer
Authors: Wang Duo , Hao Zhiguo , Hui Zijia , Wang Ke , Ding Guocheng
Published: January 2019

When an unloaded converter transformer is being energised, large inrush current may flow in the voltage jump side depending upon the residual flux in the core and the closing voltage angle of the power grid due to the hysteresis characteristics of the core, causing false operation of protective relays and bringing many adverse effects to the grid and primary electrical devices. Based on the analysis of the elimination of inrush current using controlled switching, the phase‐to‐phase electromagnetic coupling relationship which would be influenced by the core structure and winding connection mode was taken into account when considering the controlled switching strategy of three‐phase transformer. With the analysis of core residual flux after de‐energisation and the dynamic magnetisation of core during the energisation, a controlled switching strategy for inrush current restraining when energising converter transformer is presented in this study. Only the current arc quenching sequence during circuit breaker opening and the voltage extinguishing phase angle are asked for this strategy, and the simulation by electromagnetic transients programme and the experiment results indicate that this strategy could restrain the inrush transient efficiently.
Weak-lensing analysis of galaxy pairs using CS82 data
Authors: Johana Gonzalez Elizabeth , Rodriguez Facundo , García Lambas Diego , Makler Martín , Mesa Valeria , Alonso Sol , Duplancic Fernanda , Pereira Maria E. S. , Shan HuanYuan
Published: January 2019

Here we analyze a sample of close galaxy pairs (relative projected separation < 25 h−1 kpc and relative radial velocities < 350 km s−1) using a weak-lensing analysis based on the Canada-France-Hawaii Telescope Stripe 82 Survey (CS82). We determine halo masses for the total sample of pairs as well as for interacting, red, and higher-luminosity pair subsamples with ∼3σ confidence. The derived lensing signal for the total sample can be fitted either by a Singular Isothermal Sphere (SIS) with σV = 223 ± 24 km s−1 or a Navarro–Frenk–White (NFW) profile with R200 = 0.30 ± 0.03 h−1 Mpc. The pair total masses and total r band luminosities imply an average mass-to-light ratio of ∼200 h M⊙/L⊙. On the other hand, red pairs which include a larger fraction of elliptical galaxies, show a larger mass-to-light ratio of ∼345 h M⊙/L⊙. Derived lensing masses were compared to a proxy of the dynamical mass, obtaining a good correlation. However, there is a large discrepancy between lensing masses and the dynamical mass estimates, which could be accounted for by astrophysical processes such as dynamical friction, by the inclusion of unbound pairs, and by significant deviations of the density distribution from SIS and NFW profiles in the inner regions. We also compared lensing masses with group mass estimates, finding very good agreement with the sample of groups with two members. Red and blue pairs show large differences between group and lensing masses, which is likely due to the single mass-to-light ratio adopted to compute the group masses.
Modelling carbon-chain species formation in lukewarm corinos with new multi-phase models
Authors: Wang Yao , Chang Qiang , Wang Hongchi
Published: January 2019

Context. Abundant carbon-chain species have been observed towards lukewarm corinos L1527, B228, and L483. These carbon-chain species are believed to be synthesized in the gas phase after CH4 desorbs from the dust grain surface at the temperature around 30 K.

Aims. We investigate carbon-chain species formation in lukewarm corinos using a more rigorous numerical method and advanced surface chemical models. We also pay attention to the significance of the finite size effect.

Methods. We used the macroscopic Monte Carlo method in our simulations. In addition to the two-phase model, the basic multi-phase model and the new multi-phase models were used for modelling surface chemistry on dust grains. All volatile species can sublime at their sublimation temperatures in the two-phase model while most volatile species are frozen in the ice mantle before water ice sublimes in the basic and the new multi-phase models. The new multi-phase models allow more volatile species to sublime at their sublimation temperatures than the basic multi-phase model does.

Results. The significance of the finite size effect is dependent on the duration of the cold phase. The discrepancies between the rate equation approach and the Monte Carlo method decrease as the duration of the cold phase increases. When T ~ 30 K, the abundances of gaseous CH4 and CO in the two-phase model are the highest while the basic multi-phase model predicts the lowest CO and CH4 abundances among all models. The abundances of carbon-chain species in the basic and the new multi-phase models are lower than that in the two-phase model when T ~ 30 K because CH4 is crucial for the synthesis of carbon-chain species. However, because the abundance of electrons increases as the abundance of H3O+ decreases, some carbon-chain species abundances predicted by the basic multi-phase model may not be lower than that in the new multi-phase models. The two-phase model performs best in predicting carbon-chain species abundances to fit observations while the basic multi-phase model works the worst. The abundances of carbon-chain species predicted by the new multi-phase models agree reasonably well with observations.

Conclusions. The amount of CH4 can diffuse inside the ice mantle, thus sublime upon warm-up plays a crucial role in the synthesis of carbon-chain species in the gas phase. The carbon-chain species observed in lukewarm corinos may be able to gauge surface chemical models.
Carbon and oxygen in metal-poor halo stars
Authors: Amarsi A. M. , Nissen P. E. , Asplund M. , Lind K. , Barklem P. S.
Published: January 2019

Carbon and oxygen are key tracers of the Galactic chemical evolution; in particular, a reported upturn in [C/O] towards decreasing [O/H] in metal-poor halo stars could be a signature of nucleosynthesis by massive Population III stars. We reanalyse carbon, oxygen, and iron abundances in 39 metal-poor turn-off stars. For the first time, we take into account 3D hydrodynamic effects together with departures from local thermodynamic equilibrium (LTE) when determining both the stellar parameters and the elemental abundances, by deriving effective temperatures from 3D non-LTE Hβ profiles, surface gravities from Gaia parallaxes, iron abundances from 3D LTE Fe II equivalent widths, and carbon and oxygen abundances from 3D non-LTE C I and O I equivalent widths. We find that [C/Fe] stays flat with [Fe/H], whereas [O/Fe] increases linearly up to 0.75 dex with decreasing [Fe/H] down to −3.0 dex. Therefore [C/O] monotonically decreases towards decreasing [C/H], in contrast to previous findings, mainly because the non-LTE effects for O I at low [Fe/H] are weaker with our improved calculations.
Bismuth/hydroxyapatite-modified carbon screen-printed electrode for heavy-metal ion detection in aqueous media
Authors: Khan Aamir Amanat Ali , Ajab Huma , Yaqub Asim , Abdullah Mohd Azmuddin
Published: January 2019

Square-wave voltammetric stripping analysis is attractive for environmental monitoring and trace metal ion determination. The sensitivity is a result of analytes preconcentration steps on the electrode and advanced measurement procedures, where metal analytes are stripped away from the electrode at appropriate potential scan. Screen-printed electrode (SPE) has great advantages for in situ assays of heavy metal ions. Modification of SPE with bismuth (Bi) film improves the amalgamation of metal ions and the addition of hydroxyapatite (HA) increases the ion sorption, and enhances the current response due to the large porous structure and surface active sites for the metal ion binding. The ionization of the functional groups on the electrode surface upon contact with the aqueous system further assists the cation binding. The analytical performance of Bi and HA-modified SPE for simultaneous detection of Cd(II) and Pb(II) ions by square wave anodic stripping voltammetry (SWASV) was evaluated. Under the optimized electrochemical working conditions, calibration graph is linear for 240 s deposition time, in 0.1 M acetate buffer at pH 7.6 with the detection limit of 16.8 ppb for Pb(II). Two peaks corresponding to Cd(II) at -0.8 V and Pb(II) at -0.6 V can be discerned suggesting that Bi-HA modification had increased the current responses.
Design and modification of horizontal-flow roughing filter as water treatment at UGM retention pond
Authors: Mistoro Niesa Hanum , Saraswati Sri Puji
Published: January 2019

UGM Retention Pond as flood controller has its water supply from Belik River. Based on water quality monitoring results by the Environment Agency (BLH) of DIY in 2012–2016, the water status at the upstream area of Belik river has already contaminated before it flows to the retention pond. This study aims to make UGM Retention Pond not only as flood control, but also as a water treatment. The function can be fulfilled with the innovation of rough filter water type applied to horizontal flow, i.e. Horizontal-flow Roughing Filter. Mass balance analysis on the retention pond was calculated based on the assumption of the pond as a complete-mix reactor with BOD5 of 20.9 mg/L and TSS of 102 mg/L with discharge (Q) of 2.54 m3/s. The maximum target output produced for BOD5 was 3 mg/L and TSS was 50 mg/L so the target of filtering efficiency was 94 %. The analysis results showed the most optimal Horizontal-flow Roughing Filter was elongated beam-shaped design with length dimensions of 44.6 m, width of 2.5 m, and height of 1.7 m. Filter media used in the form of pebble (gravel) with the size of 24–16 mm and assumed to have permeability coefficient k = 0.1 m/s.
Water quality and sustainability of Merdada Lake, Dieng, Indonesia
Authors: Sudarmadji  , Suprayogi Slamet , Lestari Sri , Malawani Mukhamad Ngainul
Published: January 2019

The volcanic lakes in Dieng Plateau offer some unique phenomena, which interest not only tourists but also scientists. However, as the land use changes, the lakes are now facing environmental degradation especially from agricultural practices. This research aims to study the impact of agricultural practices on the environmental degradation of the lakes especially the water quality and analyze the sustainability of the lakes to support water needs. Merdada Volcanic Lake, one of the lakes in Dieng Plateau was selected as the focus of this research. Method conducted on this research are fields survey to collect the physical parameters temperature and conductivity also chemical parameters like pH, Nitrate, BOD, phosphate, and coliform. A complementary data was acquired using interviews method for defining the sustainability of the lake. Based on observation, water level of the lake is gradually decreased, especially during the dry season. At the same time, the agricultural practices in the surrounding area led to soil erosion, which involved surface runoff that transporting sediments into the lake. This research found that the practices of potato cultivation pumped out the water from Merdada Volcanic Lake and distributed over the plantation area. This practice caused a dramatic decrease in the water surface. Besides that, the agricultural practices had several adverse effects on the volcanic lakes in Dieng Plateau especially eutrophication and decrease of water quality in Merdada Lake where nitrate is over from water quality standard class II. Coliform also has an over expected value, range from 3–11 MPN/100 ml.
Comparative analysis of disaster information website based on web usability evaluation and quality content of disaster information
Authors: Agus Riyanto Indra , Abdatush Sholihah Ratri , Cahyadi Ahmad
Published: January 2019

Disaster is one of the most important researches because every country in the world has their own disaster potential. Disaster assessment improves over time due to technological and information advancements; and it is very reliant to a long period of data record. Disaster information is already available online in various websites, and is presented in form of map, data, video and multimedia contents. Each country has different disaster information standards, the Web Usability and quality of disaster-related content. This research objective is to find good model WEBUSE and quality content both national and international disaster website. National disaster website includes: Geospatial Information Agency (Badan Informasi Geospasial/BIG), Meteorological, Climatological and Geophysical Agency (Badan Meteorologi Klimatologi dan Geofisika/BMKG), National Disaster Management Authority (Badan Nasional Penanggulangan Bencana/BNPB); while international website includes: National Oceanic and Atmospheric Administration (NOAA) and United States Geological Survey (USGS). Usability comparison method uses the WEBUSE questionnaire with 4 categories, content organization and readability, navigation and links, user interface design, and performance and effectiveness; while the disaster-related content quality is measured using scoring method, with 4 categories, the geospatial information, data quality, product, and accessibility, according to United Nations Office for Disaster Risk Reduction (UNISDR). The usability level analysis for all 5 websites are classified as “good”, with USGS achieving the highest score of 0.703. As for the disaster-related quality content analysis result, USGS fulfills all categories.
Petrogenesis and depositional environment of paleozoic Sedili and Pengerang Volcaniclastics in East Johor Basin, Peninsular Malaysia
Authors: Surjono Sugeng Sapto , Leman Mohd. Shafeea , Ali Che Aziz , Mohamed Kamal Roslan , M Fathan Hanifi Mada
Published: January 2019

Volcaniclastic rocks in East Johor Basin are found in a relatively great abundance comprising Sedili and Pengerang Formations excluding the metamorphics, siliciclastics, and granites. Since the volcaniclastic rocks are found in a different formation, this study aims to find out the characteristics of each rock. Geology, petrography, and geochemical analyses were elaborated to reveal the petrogenesis and depositional environment in the studied area on the basis of fieldwork data and 24 samples collected from outcrops. The Sedili and Pengerang Formations are dominated by acidic rocks of rhyolite, rhyodacite, ignimbrite, and lava classifiied into calc-alkaline magma series which indicates a subduction-related product. Moreover, those acidic rocks are grouped into active continental margin. Eventhough volcanic rocks in Sedili and Pengerang Formations exhibit similar characteristics, they are different in several major contents. Therefore, it is inferred that both Sedili and Pengerang Formations were deposited in different phase. Coincidentally, depositional environment of both formations is also distinct. Sedili Formation were deposited in the subaerial to shallow marine, meanwhile, Pengerang Formation is interpreted to be deposited in deeper depositional setting.
Rapid Determination of Chloramphenicol in Tilapia by ultra-high performance liquid chromatography-mass spectrometry
Authors: Zeng Shaodong , Ye jianzhi , Lin Ling , Chen wuhai , Yang Chunliang
Published: January 2019

A rapid method for the determination of residues of chloramphenicol in tilapia by ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) was established. The samples were extracted with acetonitrile, and separated on a C18 column using methanol-water solution as mobile phase, and then detected under ESI- multiple reaction monitoring mode. The method showed a good linearity for the analysts over the range of 0.1-100μg/L. The detection limits were 0.10μg/kg. The recoveries ranged from 88.6% to 108% at spiked concentrations with the relative standard deviations lower than 5%. The results shows that this method has the advantages of easy to operate, fast to perform, with high sensitivity and accuracy, and it is suitable for detection of residues of chloramphenicol in tilapia.
Ultrasonic-microwave synergistic extraction of paprika pigment
Authors: Pang Min , Liu Qian , Yu Yan li , Cai Song ling
Published: January 2019

Paprika was soaked in n-hexane to extract paprika pigment by using ultrasonic and microwave assisted extraction (UMAE). The effects of different operating variables were investigated and the extraction condition was optimized through orthogonal design: ultrasonic power of 50 w, microwave power of 240 w, powder-solvent ratio of 1: 25 (g/mL), microwave time of 600 s, paprika particle size of 60 mesh. At these conditions, the color value of 147 of paprika pigment was reached. Compared with the conventional water bath extraction method, UMAE has the advantages of shorter extraction time and higher efficiency, which may be related to the effect of UMAE on destroying the cellular structure of paprika.