bluuebunny/crossref_metadata_2025 huggingface dataset:
Unique low-molecular-weight lignin with high purity extracted from wood by deep eutectic solvents (DES): a source of lignin for valorization
Authors: Alvarez-Vasco Carlos , Ma Ruoshui , Quintero Melissa , Guo Mond , Geleynse Scott , Ramasamy Karthikeyan K. , Wolcott Michael , Zhang Xiao
Published: June 2016

This paper reports a new method of applying Deep Eutectic Solvents (DES) for extracting lignin from woody biomass with high yield and high purity.
Modification of PDMS to fabricate PLGA microparticles by a double emulsion method in a single microfluidic device
Authors: Montazeri Leila , Bonakdar Shahin , Taghipour Mojtaba , Renaud Philippe , Baharvand Hossein
Published: June 2016

We present an easy, durable method to generate a partially hydrophilic/hydrophobic poly(dimethylsiloxane) (PDMS) microfluidic device.
Imaging the position-dependent 3D force on microbeads subjected to acoustic radiation forces and streaming
Authors: Lamprecht Andreas , Lakämper Stefan , Baasch Thierry , Schaap Iwan A. T. , Dual Jurg
Published: June 2016

An optical trap is used to measure the forces that particles experience in a microfluidic channel during acoustic manipulation.
A microfluidic study of liquid–liquid extraction mediated by carbon dioxide
Authors: Lestari Gabriella , Salari Alinaghi , Abolhasani Milad , Kumacheva Eugenia
Published: June 2016

Liquid–liquid extraction is an important separation and purification method; however, it faces a challenge in reducing the energy consumption and the environmental impact of solvent (extractant) recovery. An oscillatory microfluidic platform is proposed to study reactive liquid–liquid extraction involving switchable solvents and carbon dioxide gas.
Deciphering the CHEF-PET-ESIPT liaison mechanism in a Zn2+ chemosensor and its applications in cell imaging study
Authors: Jana Atanu , Das Bhriguram , Mandal Sushil K. , Mabhai Subhabrata , Khuda-Bukhsh Anisur R. , Dey Satyajit
Published: June 2016

Proper fusion of fluorescence mechanisms in a single fluorophore unit is highly desirable to obtain better sensitivity, as well as selectivity towards a particular metal ion.
Eight rare earth metal organic frameworks and coordination polymers from 2-nitroterephthlate: syntheses, structures, solid-state luminescence and an unprecedented topology
Authors: Smith Jermaine A. , Singh-Wilmot Marvadeen A. , Carter Korey P. , Cahill Christopher L. , Lough Alan J. , Knee Christopher S.
Published: June 2016

An unprecedented report of eight lanthanide(iii) CPs and MOFs from 2-nitroterephthalate which feature four network types, including one novel topology.
Investigation of supramolecular architectures of bent-shaped pyridine derivatives: from a three-ring crystalline compound towards five-ring mesogens
Authors: Trišović Nemanja , Antanasijević Jelena , Rogan Jelena , Poleti Dejan , Tóth-Katona Tibor , Salamonczyk Miroslaw , Jákli Antal , Fodor-Csorba Katalin
Published: June 2016

The mesomorphic properties of new bent-core mesogens, coupled with the detailed analysis of the molecular packing of the related three-ring compounds is presented.
Stereoselective synthesis and antitumoral activity of Z-enyne pseudoglycosides
Authors: Dantas Claudio R. , de Freitas Jucleiton J. R. , Barbosa Queila P. S. , Militão Gardenia C. G. , Silva Thiago D. S. , da Silva Teresinha G. , Paulino Antônio A. S. , Freitas Juliano C. R. , Oliveira Roberta A. , Menezes Paulo H.
Published: June 2016

The stereoselective synthesis and antitumoral activity of Z-enyne pseudoglycosides is described.
Preparation of highly cross-linked raspberry-like nano/microspheres and surface tailoring for controlled immunostimulating peptide adsorption
Authors: Du Chunbao , Zhang Nan , Ding Shichao , Gao Xumian , Guan Ping , Hu Xiaoling
Published: June 2016

The surface functionalities of ionic liquid-functionalized nano/microspheres with a highly cross-linked raspberry-like structure could be well controlled by adjusting the functional chains appropriately.
One-step, solvent-free mechanosynthesis of silver nanoparticle-infused lignin composites for use as highly active multidrug resistant antibacterial filters
Authors: Rak Monika J. , Friščić Tomislav , Moores Audrey
Published: June 2016

Polyacrylamide embedded silver nanoparticles were synthesized from silver salts in a solvent-free fashion by ball milling mechanochemistry, with lignin as a biodegradable reducer, and used as highly efficient antibacterial plugs.
Anisotropic thermal conductivity and mechanical properties of phagraphene: a molecular dynamics study
Authors: Pereira Luiz Felipe C. , Mortazavi Bohayra , Makaremi Meysam , Rabczuk Timon
Published: June 2016

In-plane anisotropy in the thermal conductivity of phagraphene.
A tetrapeptide from maize protects a transgenic Caenorhabditis elegans Aβ1-42model from Aβ-induced toxicity
Authors: Zhang Zhixian , Ma Heran , Wang Xiaoying , Zhao Ziyuan , Zhang Yue , Zhao Baolu , Guo Yi , Xu Li
Published: June 2016

A food-derived bioactive peptide that works as an important antioxidantin vivocould be used to remedy oxidative stress-related diseases.
Air purifier devices based on adsorbents produced from valorization of different environmental hazardous materials for ammonia gas control
Authors: Mohamed Elham F. , Sayed Ahmed Sohair A. , Abdel-Latif Nasser M. , EL-Mekawy Asmaa
Published: June 2016

The present study aimed to find a beneficial solution for waste recycling and disposal by converting it from an environmental load to products useful for air pollution control.
Enhanced hydroxide conductivity of imidazolium functionalized polysulfone anion exchange membrane by doping imidazolium surface-functionalized nanocomposites
Authors: Li Jianwei , Yan Xiaoming , Zhang Yuyan , Zhao Baolin , He Gaohong
Published: June 2016

A new method was proposed to prepare a membrane with regional aggregation of functional groups by incorporating nanocomposites surface-functionalized with a large number of functional groups.
Three-dimensional In2O3–CuO inverse opals: synthesis and improved gas sensing properties towards acetone
Authors: Xing Ruiqing , Sheng Kuang , Xu Lin , Liu Wei , Song Jian , Song Hongwei
Published: June 2016

Specific three-dimensional inverse opal (3DIO) In2O3–CuO architecture with additional via-holes was first prepared by a simple sacrificial template method.
Construction of nitrogen-doped graphene quantum dots-BiVO4/g-C3N4Z-scheme photocatalyst and enhanced photocatalytic degradation of antibiotics under visible light
Authors: Yan Ming , Zhu Fangfang , Gu Wei , Sun Lin , Shi Weidong , Hua Yinqun
Published: June 2016

In this study, an effective nitrogen-doped graphene quantum dots (NGQDs)-BiVO4/g-C3N4Z-scheme heterojunction has been successfully prepared for environmental remediation.
Characterization of condensed aromatics and heteroatomic species in Yanshan petroleum coke through ruthenium ion-catalyzed oxidation using three mass spectrometers
Authors: Lv Jing-Hui , Wei Xian-Yong , Wang Ying-Hua , Wang Tie-Min , Liu Jing , Zhang Dong-Dong , Zong Zhi-Min
Published: June 2016

Ruthenium ion-catalyzed oxidation of Yanshan petroleum coke (YPC) was performed to characterize condensed aromatics and heteroatomic species in YPC.
Moderately oxidized graphene–carbon nanotubes hybrid for high performance capacitive deionization
Authors: Zhang Helan , Liang Peng , Bian Yanhong , Jiang Yong , Sun Xueliang , Zhang Changyong , Huang Xia , Wei Fei
Published: June 2016

Moderately oxidized graphene–carbon nanotubes hybrid can be used as good electrode materials for CDI with enhanced electrosorption capacity.
Unimolecular micelles from graft copolymer with binary side chains
Authors: Mo Yangmiao , Lin Shudong , Tu Yuanyuan , Liu Guojun , Hu Jiwen , Liu Feng , Song Jun
Published: June 2016

A novel amphiphilic binary graft copolymer was synthesized and used to prepare unimolecular micelles by intramolecular association.
Design and synthesis of new ruthenium complex for dye-sensitized solar cells
Authors: Murali M. G. , Wang Xingzhu , Wang Qing , Valiyaveettil Suresh
Published: June 2016

Ruthenium complexes incorporated with carbazole, fluorine and phenothiazine units with dipyrido[3,2-a:3′-2′-c]phenazine are synthesized and photovoltaic properties are investigated.
On the mechanism of retro-Diels–Alder reaction of partially saturated 2-pyrones to produce biorenewable chemicals
Authors: Gupta Shelaka , Alam Md. Imteyaz , Khan Tuhin Suvra , Sinha Nishant , Haider M. Ali
Published: June 2016

Partially saturated 2-pyrone molecules undergo ring-opening and decarboxylation via retro-Diels–Alder (rDA) reaction.
Silica-aerogel-powders “jammed” polyimide aerogels with excellent hydrophobicity and conversion to ultra-light polyimide aerogel
Authors: Wu Shuai , Du Ai , Xiang Youlai , Liu Mingfang , Li Tiemin , Shen Jun , Zhang Zhihua , Li Conghang , Zhou Bin
Published: June 2016

In this paper, SAp play a role as the shrinkage inhibiter to fabricate the SAp “jammed” polyimide gels.
Photocleavable amphiphilic diblock copolymer with an azobenzene linkage
Authors: Wang Jilei , Ouyang Yiyun , Li Shang , Wang Xiaogong , He Yaning
Published: June 2016

Diblock copolymer with an azobenzene linkage can be efficiently photocleaved upon UV light irradiation. Thus, the colloidal aggregates of this kind of amphiphilic diblock copolymer will be disrupted due to the cleavage of the azobenzene junction.
Catalyst-free site-specific surface modifications of nanocrystalline diamond films via microchannel cantilever spotting
Authors: Davydova Marina , de los Santos Pereira Andres , Bruns Michael , Kromka Alexander , Ukraintsev Egor , Hirtz Michael , Rodriguez-Emmenegger Cesar
Published: June 2016

Microchannel cantilever spotting is combined with a copper-free click chemistry ligation to achieve the patterning of nanocrystalline diamond films.
Efficient and stable polymer solar cells with electrochemical deposition of CuSCN as an anode interlayer
Authors: Fu Ping , Guo Xin , Wang Zhiliang , Yu Shuwen , Zhou Lingyu , Yu Wei , Zhang Jian , Li Can
Published: June 2016

Electrochemical deposition (ECD) of a copper thiocyanate (CuSCN) film as an efficient anode interlayer (AIL) in polymer solar cells (PSCs) is reported.
Oxidation of free, peptide and protein tryptophan residues mediated by AAPH-derived free radicals: role of alkoxyl and peroxyl radicals
Authors: Fuentes-Lemus E. , Dorta E. , Escobar E. , Aspée A. , Pino E. , Abasq M. L. , Speisky H. , Silva E. , Lissi E. , Davies M. J. , López-Alarcón C.
Published: June 2016

When AAPH is employed as a free radical source, at low concentrations of free, peptide and protein Trp residues, the oxidation is mostly induced by alkoxyl radicals. However, at high concentrations, both peroxyl and alkoxyl radicals are involved.
Metallacarboranes as tunable redox potential electrochemical indicators for screening of gene mutation
Authors: García-Mendiola Tania , Bayon-Pizarro Victoria , Zaulet Adnana , Fuentes Isabel , Pariente Félix , Teixidor Francesc , Viñas Clara , Lorenzo Encarnación
Published: June 2016

The electrochemical behaviour of metallocarborane sodium salts and their interactions with DNA have been studied. They are shown to be selective redox indicators with wide-ranging potential as electrochemical indicators in DNA biosensors.
Rational confinement of molybdenum based nanodots in porous carbon for highly reversible lithium storage
Authors: Deng Xiang , Zhao Bote , Zhong Yijun , Zhu Yanping , Shao Zongping
Published: June 2016

A rational synthesis route towards <5 nm transition metal-based nanodots confined in a highly porous carbon matrix is proposed without adding external carbon sources and applied for highly reversible lithium storage.
A PCBM-assisted perovskite growth process to fabricate high efficiency semitransparent solar cells
Authors: Li Chao , Sleppy Joseph , Dhasmana Nitesh , Soliman Mikhael , Tetard Laurene , Thomas Jayan
Published: June 2016

Developing highly efficient semitransparent perovskite solar cells in a simple and rapid fashion will open the window for their applications in integrated photovoltaics.
In vitro corrosion behaviour and anti-Candida spp. activity of Zn coated with ZnO-nanostructured ‘Anastacia’ flowers
Authors: Alves Marta M. , Cunha Diana V. , Santos Catarina F. , Mira Nuno P. , Montemor Maria F.
Published: June 2016

Rejection and colonization by microbes are two problematic issues that often require surgical removal of medical implants. The functionalization of Zn surfaces with ZnO-nanostructured ‘Anastacia’ flowers (NAF) can potentially overcome these important drawbacks further boosting the use of Zn in biomedical implants.
Selective colorimetric detection of Cu2+by lanthanide based hybrid complexes associated with a single crystal growth mediated transformation
Authors: Roy Soumyabrata , Chanu Oinam Bijeta , Sarkar Sumanta , Peter Sebastian C.
Published: June 2016

Two Ln based (Dy and Nd) hybrid complexes were synthesized and their properties were studied. The Dy complex showed selective coinage metal detection while the Nd one showed highly selective Cu2+detection.
Transient mechanochromism in epoxy vitrimer composites containing aromatic disulfide crosslinks
Authors: Ruiz de Luzuriaga Alaitz , Matxain Jon M. , Ruipérez Fernando , Martin Roberto , Asua José M. , Cabañero Germán , Odriozola Ibon
Published: June 2016

Dynamic crosslinks based on 4-aminophenyl disulfide are responsible for a transient mechanochromism, due to the formation of sulfenyl radicals.
E2F and GATA switches turn off WD repeat domain 77 expression in differentiating cells
Authors: Yu Min , Wang Ulrica , Wang Zhengxin
Published: June 2016

WDR77 (WD repeat domain 77) is expressed during earlier lung development when cells are rapidly proliferating, but is absent from adult lung. It is re-activated during lung tumorigenesis and is essential for lung cancer cell proliferation. Signalling pathways/molecules that control WDR77 gene expression are unknown. Promoter mapping, gel shift assay and ChIP revealed that the WDR77 promoter contains bona fide response elements for E2F and GATA transcriptional factors as demonstrated in prostate cancer, lung cancer and erythroid cells, as well as in mouse lung tissues. The WDR77 promoter is transactivated by E2F1, E2F3, GATA1 and GATA6, but suppressed by E2F6, GATA1 and GATA3 in prostate cancer PC3 cells. WDR77 expression is associated with E2F1, E2F3, GATA2 and GATA6 occupancy on the WDR77 gene, whereas, in contrast, E2F6, GATA1 and GATA3 occupancy is associated with the loss of WDR77 expression during erythroid maturation and lung development. More importantly, the loss of WDR77 expression that results from E2F and GATA switches is required for cellular differentiation of erythroid and lung epithelial cells. In contrast, lung cancer cells avoid post-mitotic differentiation by sustaining WDR77 expression. Altogether, the present study provides a novel molecular mechanism by which WDR77 is regulated during erythroid and lung development and lung tumorigenesis.
Compact ECDSA engine for IoT applications
Authors: Yalçin T.
Published: June 2016

Security problems introduced with rapid increase in deployment of Internet‐of‐Things devices can be overcome only with lightweight cryptographic schemes and modules. A compact prime field (GF(p)) elliptic curve digital signature algorithm (ECDSA) engine suitable for use in such applications is presented. Generic architecture of the engine makes it suitable for other elliptic curve (EC) based schemes (EC Diffie–Hellman key exchange, EC integrated encryption, EC factoring etc.) with slight modifications. The presented engine is composed of a simple microcoded controller and application‐specific processing units. It can work with ECs of up to 256 bits, while 160‐bit ECDSA signature generation takes 490 K cycles. The engine is implemented as an intellectual property (IP) in a 180 nm process. However, its architecture allows it to be implemented on any application specific integrated circuit (ASIC) or FPGA platform with dual‐port memory support. In view of its gate count of 11,366 gate equivalents, the presented work is the most compact ECDSA engine with capability for a wide range of curves and different applications.
Novel local bit‐plane dissimilarity pattern for computed tomography image retrieval
Authors: Dubey Shiv Ram , Singh Satish Kumar , Singh Rajat Kumar
Published: June 2016

The performance of any image retrieval system relies over the image descriptor used for matching. The recently proposed descriptors mainly suffer due to the ‘less discriminative power’ and ‘curse of dimensionality’. A novel image descriptor using local bit‐plane dissimilarity pattern (LBDISP) is introduced. The descriptor is computed by finding the dissimilarity map between the centre pixel and its neighbours over each bit‐plane. The relationship between the centre pixel and dissimilarity map is then encoded to form the LBDISP descriptor. The dimension of the descriptor depends upon the number of neighbours only. A retrieval experiment over NEMA‐CT database confirms the superiority and efficiency of the LBDISP descriptor.
Temperature‐variation‐based hardware Trojan detection through ring oscillator
Authors: Zhong Jingxin , Wang Jianye , Ding Hao
Published: June 2016

Hardware Trojan (HT) insertions have emerged as a major security concern for integrated circuits. HT can cause undesired change in functional behaviour, while it also changes the temperature characteristic of the chip. A temperature variation‐based HT detection technique through ring oscillator is proposed. Ring‐oscillator is a thermally sensitive digital oscillator, and the number of oscillations that the counter counts varies with temperature. It is shown that the ring oscillator's count in a chip with HT insertion in a fixed duration drops faster. With this count, statistical analysis finds that the deviation between the maximum and minimum value in a chip without HT insertion is approximate to another, while HT insertion will cause the deviation value extend. Then, we present a Trojan detection approach using ring oscillator's count analysis. Experimental results show that the proposed approach achieves more effective and easier for Trojan detection. Moreover, the proposed detection approach can be used to detect different HT insertion in different place on the chips.
Low‐complexity EDAS and low‐complexity detection scheme for MPSK spatial modulation
Authors: Balmahoon Tarika , Xu Hongjun
Published: June 2016

Euclidean‐distance antenna selection (EDAS) is an effective transmit AS technique for spatial modulation (SM). This study presents a low‐complexity (LC) EDAS scheme for the M‐ary phase shift keying (MPSK) SM. The LC‐EDAS for MPSK SM (LC‐MPSK‐EDAS) is achieved by exploiting the rotational symmetry of the MPSK constellation and using singular value decomposition (SVD_EDAS) for factorisation of the modified channel matrix. A further reduction in complexity is achieved by eliminating the process of conditioning on elements of the MPSK symbol set. The complexity of the proposed scheme is independent of the order M of MPSK. Also, in this study, an LC near maximum likelihood (ML) detection scheme for MPSK SM systems, signal vector‐based detection (SVD), is implemented. Though this scheme provides poor results when using the M‐ary quadrature amplitude modulation constellation, it is found that the error performance of this scheme for MPSK constellations has very near ML results. The simulation results show that even at high signal‐to‐noise values this scheme maintains near ML performance. To support the results, the closed‐form expression of the bit error rate for the MPSK constellation is derived.
Design of new digital blind feedforward timing recovery algorithm for linear modulations in digital communication receivers
Authors: Ayat Mehdi , Mirzakuchaki Sattar , Beheshti‐Shirazi Ali Asghar
Published: June 2016

Synchronisers are a significant part of digital communication receivers since they are used to estimate the received signal timing. Among these synchronisers, non‐data‐aided (NDA) or blind synchronisers are even more important due to bandwidth efficiency. In this study, a different approach is investigated to derive new feedforward NDA timing estimators based on Newton algorithm. Two novel estimators with four and two samples per symbol are presented and compared with traditional timing estimators, respectively. One of the main advantages of the second proposed estimator is the ability to control the loop gain automatically. This ability improves the convergence speed and robustness of the design. Simulation results show that the presented estimators outperform the conventional estimators over a noisy channel, especially at small excess bandwidth and low signal to noise ratio.
Operation of a hybrid modular multilevel converter during grid voltage unbalance
Authors: Amankwah Emmanuel K. , Watson Alan J. , Clare Jon C.
Published: June 2016

The recently proposed parallel hybrid modular multilevel converter is considered to be a low loss, low component count converter with soft switching capability of the ‘main’ H‐bridge. The converter has similar advantages to other emerging modular multilevel converter circuits being considered for high‐voltage, direct current power transmission and can be made compact which is desirable for offshore application. However, during ac network unbalance the individual ‘chain‐links’ (CL) exchange unequal amounts of power with the grid which requires appropriate remedial action. This study presents research into the performance of the converter and proposes a suitable control method that enables the converter to operate during grid voltage unbalance. The proposed control concept involves the use of asymmetric third harmonic voltage generation in the ‘CL’ of the converter to redistribute the power exchanged between the individual ‘CL’ and the grid. Mathematical analysis and simulation modelling with results are presented to support the work described.
Effects of QV curves in the dynamic behaviour of power systems
Authors: Moura Renan S. , Zambroni de Souza Antonio Carlos , Lopes Benedito Isaias Lima , Mohn Fritz Walter
Published: June 2016

This study addresses some issues related to reactive power support in electric power systems. This study considers the QV curve as a tool for indicating the robustness of generators in terms of their reactive power margin (RPM). The QV curve yields information that is then considered for contingency studies. Then, the dynamic behaviour of a system with respect to the RPM is investigated. A positive margin, the study shows, may drive a system to instability. To move the system to a secure region, fuzzy logic is proposed and the effects are dynamically analysed. To simulate the proposed methodology, the study employs a sample system of five buses and a real Brazilian system.
Disturbance propagation mechanism based on the electromechanical wave theory
Authors: Bi Tianshu , Qin Junda , Yan Yuehao , Liu Hao , Martin Kennth E.
Published: June 2016

With the development of power grid interconnection, the disturbances propagation behave as a sort of electromechanical waves. The study of the disturbance propagation mechanism in the interconnected power networks is of great importance for controlling the spreading of disturbance and improving the security level of power systems. In this study, the electromechanical wave equation is built based on the discrete inertia model of power networks. In order to describe the phase and amplitude variations, the wave transfer function is derived. Then, the propagation characteristics of different frequency disturbances are analysed. The corner frequency of the discrete inertia model is proposed. Furthermore, the frequency dispersion and local oscillation are revealed as well as their relationships with corner frequency. Computer simulations for a 50‐generator chain network are used to verify the propagation characteristics of disturbances with different frequencies. The research work is beneficial to analyse the influence of disturbance and develop countermeasures for disturbance based on electromechanical wave theory.
Power system energy stability region based on dynamic damping theory
Authors: Ma Jing , Wang Shangxing , Wang Zengping , Qiu Yang , Thorp James S.
Published: June 2016

Concerning the difficulty in quantitatively describing the influence of different disturbances on power system stability, a novel composite energy stability region (ESR) is proposed in this study based on the dynamic damping theory. First, considering the influence of time‐variant factors in the oscillation process on the dynamic characteristics of the system, the dynamic damping is energized. Thus power system dynamic stability criteria considering both the disturbance magnitude and system operation state is obtained. Then, the energy boundary of ESR is determined in the energy space according to the criteria, and the parameter boundary of ESR is determined in the parameter space combining the small signal stability region. On this basis, in the parameter‐energy multi‐dimensional space, the ESR which could reflect the dynamic stability and transient stability of power system under different disturbances is established. Finally, the ESR of IEEE 4‐machine 11‐bus system is drafted based on the dynamic damping theory. Simulation analysis of different parameter‐energy pairs inside and outside the ESR verifies the correctness of the ESR drafted. The research in this study is of significant value in guiding system dispatch, predicting potential risks, formulating control strategies, and guaranteeing the safe and stable operation of power system.
Comprehensive power transfer distribution factor model for large‐scale transmission expansion planning
Authors: Rahmani Mohsen , Kargarian Amin , Hug Gabriela
Published: June 2016

Transmission expansion planning (TEP) is an important and computationally expensive decision‐making process in power systems. Expression of the power flows using power transfer distribution factors (PTDFs) could potentially reduce the size and computational cost of the TEP. However, this formulation does not lend itself easily for this problem as the system topology changes in the course of the optimisation procedure. This study presents a PTDF‐based TEP model devoid of voltage angles and nodal power balances, while producing the same solution as angle‐based TEP models. The proposed model is capable of monitoring a limited number of transmission lines that have significant impact on the system's reliable and optimal operation. It thus considerably reduces the number of constraints and results in a scalable optimisation problem. The proposed model is highly advantageous especially for the TEP of large‐scale power systems. The numerical results provide an indication for the effectiveness of the proposed model.
Risk‐based placement of TCSC for transient stability enhancement
Authors: Abapour Mehdi , Aliasghari Parinaz , Haghifam Mahmoud‐Reza
Published: June 2016

TCSC is one of the most appropriate devices to improve the transient stability of power systems. Since in today's competitive environment, investments in power systems need to be cost‐effective, in this study, a procedure is presented to determine whether using TCSC for transient stability improvement is cost‐effective or not. To this purpose, the transient instability risk is estimated both with and without TCSC. Afterwards, a comparison is made between the amount of improvement made in transient instability risk and the investment cost of TCSC. In the proposed procedure, the probabilities of transient instability and its cost are used to estimate the transient instability risk. To calculate the transient instability probability, a conditional method is used. This method is applied on the IEEE 9‐bus as well as New England test systems. The simulation results demonstrate that the proposed procedure is capable of determining the cost–benefit size and number of TCSC units. Furthermore, results indicate that in some cases, installing TCSC to only improve transient stability is devoid of monetary value.
Optimal capacitor placement in distribution networks regarding uncertainty in active power load and distributed generation units production
Authors: Jannat Mohamed B. , Savić Aleksandar S.
Published: June 2016

The paper proposes a new method for optimal allocation of shunt capacitors in distribution network with renewable distributed generation units such as wind turbines and/or solar power plants. The proposed method, based on application of the Monte Carlo simulation methods, respects the uncertainties associated with load demand and renewable sources power production. The optimisation problem is modelled by two criterion functions with the aim of improving voltage profile in a network by optimal selection of the locations and installed powers of the shunt capacitors. The suggested criterion functions have been optimised simultaneously by applying the non‐dominated sorting genetic algorithm. On the basis of the measured data on wind speed and solar radiation, the method has been tested by the example of a real distribution network.
Optimal planning of plug‐in hybrid electric vehicle charging station in distribution network considering demand response programs and uncertainties
Authors: Shojaabadi Saeed , Abapour Saeed , Abapour Mehdi , Nahavandi Ali
Published: June 2016

This study presents a mathematical model to determine the optimal site and the size of plug‐in hybrid electric vehicles charging stations (CSs) in the distribution networks. The presented optimal planning is done along with considering the rate of customers’ participation in demand response programs (DRPs) at the presence of some uncertainties associated with the load values and electricity market price. In order to model the load, time‐of‐use DRP is used. The proposed model involves distribution system manager (DSM) benefit maximising derived from the appropriate use of CS for charging and discharging vehicle batteries, reliability improvement and supplying network's load demand at peak times as the objective function, technical limitation as constraint and the siting and sizing of electric vehicles CS as optimisation variables. The genetic algorithm method with embedded Monte Carlo simulation is used in order to solve the optimisation problem and is applied to the 9‐bus and 33‐bus networks. The test results indicate that not only does the appropriate planning have an economic benefit for DSM, but also voltage profile and power supply reliability for customers can be improved and active power losses can also be reduced.
Three‐phase probabilistic load flow for power system with correlated wind, photovoltaic and load
Authors: Ran Xiaohong , Miao Shihong
Published: June 2016

In order to evaluate impact of different uncertainty, such as the intermittent behaviour of wind power and photovoltaic (PV) generation and bus load, and adjacent wind farms or PV resources on performance of power system, a new three‐phase probabilistic load flow (PLF) algorithm with asymmetric line parameter and unbalanced load of distribution system is proposed. Correlation among input random variables is considered, especially the joint correlation of wind power and PV generation and bus loads is considered, and then joint probabilistic model of wind power, PV generation and bus load is established. Then a joint cumulants method and Gram–Charlier expansion are applied to obtain the cumulative distribution function of desired random variables, and PLF results based on joint cumulants method are compared with the ones of Monte Carlo simulations. Proposed method allows evaluating potential impact of different correlation and renewable energy generation penetration on the PLF of power system. The effectiveness of proposed method is demonstrated with a typical structure of 25‐bus distribution system.
Human dynamics based driver model for autonomous car
Authors: Li Lin , Liu Yanheng , Wang Jian , Deng Weiwen , Oh Heekuck
Published: June 2016

This study presents a new driver model based on human behaviour dynamics for autonomous cars, which allows driverless cars to move appropriately in accordance to the behavioural features of driver owners. This model is established through analysing drivers’ various properties, e.g. gender, age, driving experience, personality, and emotion. These attributes collectively determine all the actions occurred during the driving process. Through analysing the statistical data gathered during the simulation, the authors find that the proposed model can reflect the power‐law distribution with respect to the concerned human behaviours. Finally, the proposed model is validated by the hardware‐in‐loop simulator and real driving experiment.
Comparison of supersonic bullet ballistic models for accurate localisation of small arms fire
Authors: Lo Kam W. , Ferguson Brian G.
Published: June 2016

This study evaluates and compares the accuracies of five different ballistic models in predicting the speed profile of a supersonic bullet using radar measured speed data for 36 types of bullets. Each of the five ballistic models is parameterised by a ballistic constant and the muzzle speed of the bullet. In practice, each of these two parameters spans a wide range of values because of the large number of different bullet types that are available for use in a variety of applications. For a given bullet type, the bullet's ballistic constant and muzzle speed are determined by fitting the ballistic model to the data in a least‐squares (LS) sense, and the root‐mean‐square (RMS) and maximum absolute (MA) deviations of the LS fit of the model from the data are computed. The best ballistic model (out of the five) is the one that has the smallest RMS and MA errors for the maximum number of bullet types. This ballistic model has been applied to accurate ranging of small arms fire using a single sensor node, with and without a priori knowledge of the model parameters, and its effectiveness for both cases is demonstrated using real data recorded from a field experiment.
Non‐linear autoregressive moving average with exogenous input model‐based adaptive control of a wind energy conversion system
Authors: Subudhi Bidyadhar , Ogeti Pedda Suresh
Published: June 2016

Wind energy conversion system (WECS) is a stochastic system, since wind speed varies intermittently. Therefore a non‐linear autoregressive moving average with exogenous input (NARMAX) model is developed to represent the dynamics of WECS which is used for real‐time implementation. In a doubly‐fed induction generator (DFIG) WECS, speed and power are the outputs for regulation which are achieved by controlling the torque and pitch angle, repetitively. NARMAX model identifies the structure and significant terms of speed and power of DFIG WECS and its parameters are estimated employing an on‐line adaptive recursive least squares algorithm. For optimisation of torque and pitch angle, performance index (PI) is defined in non‐linear adaptive model predictive controller (NAMPC) to achieve the control objective, i.e. torque and pitch angle. The weights in PI are updated until the optimised values in control inputs (torque and pitch control) are achieved. Boundedness of the WECS is defined by considering the constraints on the outputs and control inputs. Extensive simulations are carried out with NARMAX structure with NAMPC on DFIG WECS using MATLAB/SIMULINK and the performance is compared with conventional proportional–integral controller and model predictive control. From the obtained results, it is observed that the NARMAX model with NAMPC has minimum deviations from the operating point in power, speed, torque and pitch angle compared to other controllers.
Reduction in non-(k+ 1)-power-free morphisms
Authors: Wlazinski Francis
Published: June 2016

Under some hypotheses, if the image by a morphism of a (k+ 1)-power-free word contains a (k+ 1)-power, we can reduce this word to obtain a new word with the same scheme. These hypotheses are satisfied in the case of uniform morphisms. This allows us to state that, whenk≥ 4, ak-power-free uniform morphism is a (k+ 1)-power-free morphism.
High-performance radio frequency transistors based on diameter-separated semiconducting carbon nanotubes
Authors: Cao Yu , Che Yuchi , Seo Jung-Woo T. , Gui Hui , Hersam Mark C. , Zhou Chongwu
Published: June 2016

In this paper, we report the high-performance radio-frequency transistors based on the single-walled semiconducting carbon nanotubes with a refined average diameter of ∼1.6 nm. These diameter-separated carbon nanotube transistors show excellent transconductance of 55 μS/μm and desirable drain current saturation with an output resistance of ∼100 KΩ μm. An exceptional radio-frequency performance is also achieved with current gain and power gain cut-off frequencies of 23 GHz and 20 GHz (extrinsic) and 65 GHz and 35 GHz (intrinsic), respectively. These radio-frequency metrics are among the highest reported for the carbon nanotube thin-film transistors. This study provides demonstration of radio frequency transistors based on carbon nanotubes with tailored diameter distributions, which will guide the future application of carbon nanotubes in radio-frequency electronics.
Fingering instability of a suspension film spreading on a spinning disk
Authors: Kulkarni Mayuresh , Sahoo Subhadarshinee , Doshi Pankaj , Orpe Ashish V.
Published: June 2016

The spreading of a thin film of suspension on a spinning disk and the accompanying contact line instability is studied through flow visualization experiments. The critical radius for the onset of instability shows an increase with increase in the particle fraction (ϕp) before decreasing slightly at the highest value of ϕp studied, while the instability wavelength (λ) exhibits a non-monotonic dependence. The value of λ is close to that for a partially wetting liquid at lower ϕp, it decreases with increasing ϕp to a minimum before increasing again at largest ϕp. The non-monotonic trends observed for λ are discussed in light of the linear stability analysis of thin film equations derived for suspensions by Cook et al. [“Linear stability of particle-laden thin films,” Eur. Phys. J.: Spec. Top. 166, 77 (2009)] and Balmforth et al. [“Surface tension driven fingering of a viscoplastic film,” J. Non Newtonian Fluid Mech. 142, 143 (2007)].
Scaling laws for gas breakdown for nanoscale to microscale gaps at atmospheric pressure
Authors: Loveless Amanda M. , Garner Allen L.
Published: June 2016

Electronics miniaturization motivates gas breakdown predictions for microscale and smaller gaps, since traditional breakdown theory fails when gap size, d, is smaller than ∼15 μm at atmospheric pressure, patm. We perform a matched asymptotic analysis to derive analytic expressions for breakdown voltage, Vb, at patm for 1 nm ≤ d ≤ 35 μm. We obtain excellent agreement between numerical, analytic, and particle-in-cell simulations for argon, and show Vb decreasing as d → 0, instead of increasing as predicted by Paschen's law. This work provides an analytic framework for determining Vb at atmospheric pressure for various gap distances that may be extended to other gases.
On a class of nonlocal wave equations from applications
Authors: Beyer Horst Reinhard , Aksoylu Burak , Celiker Fatih
Published: June 2016

We study equations from the area of peridynamics, which is a nonlocal extension of elasticity. The governing equations form a system of nonlocal wave equations. We take a novel approach by applying operator theory methods in a systematic way. On the unbounded domain ℝn, we present three main results. As main result 1, we find that the governing operator is a bounded function of the governing operator of classical elasticity. As main result 2, a consequence of main result 1, we prove that the peridynamic solutions strongly converge to the classical solutions by utilizing, for the first time, strong resolvent convergence. In addition, main result 1 allows us to incorporate local boundary conditions, in particular, into peridynamics. This avenue of research is developed in companion papers, providing a remedy for boundary effects. As main result 3, employing spherical Bessel functions, we give a new practical series representation of the solution which allows straightforward numerical treatment with symbolic computation.
High dynamic range emission measurements of shocked energetic materials: Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX)
Authors: Bassett Will P. , Dlott Dana D.
Published: June 2016

A new emission apparatus with high time resolution and high dynamic range was used to study shock-induced ignition of octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine in the form of ultrafine powder (4 ± 3 μm particle size), over a range of impact velocities (0.8–4.3 km s−1) and impact durations (2.5–16 ns). A graybody model was used to extract graybody emissivities and time-dependent temperatures from a few ns to 100 μs. The emission transients consisted of three parts: a 6700 K nanosecond burst during the shocks, a 4000–4500 K temperature spike near 0.3 μs followed by a ∼3300 K tail extending out to ∼100 μs. These temperatures varied remarkably little with impact velocity and duration, while the emission intensities and emissivities changed by over an order of magnitude. The emissivity changes were interpreted with a hot spot model, where hot spot temperatures reached a maximum of 6700 K and the hot spot volume fractions increased from 5% to 100% as impact velocity increased from 1 to 3 km s−1. Changing shock durations in the 2.5–16 ns range had noticeable effects on the microsecond emission. The 0.3 μs temperature spike was much smaller or absent with 2.5 ns shocks, but prominent with longer durations. An explanation for these effects was put forth that invoked the formation of carbon-rich clusters during the shock. In this view, cluster formation was minimal with 2.5 ns shocks, but longer-duration shocks produced increasingly larger clusters, and the 0.3 μs temperature spikes represented cluster ignition.
Constitutive modeling of large inelastic deformation of amorphous polymers: Free volume and shear transformation zone dynamics
Authors: Voyiadjis George Z. , Samadi-Dooki Aref
Published: June 2016

Due to the lack of the long-range order in their molecular structure, amorphous polymers possess a considerable free volume content in their inter-molecular space. During finite deformation, these free volume holes serve as the potential sites for localized permanent plastic deformation inclusions which are called shear transformation zones (STZs). While the free volume content has been experimentally shown to increase during the course of plastic straining in glassy polymers, thermal analysis of stored energy due to the deformation shows that the STZ nucleation energy decreases at large plastic strains. The evolution of the free volume, and the STZs number density and nucleation energy during the finite straining are formulated in this paper in order to investigate the uniaxial post-yield softening-hardening behavior of the glassy polymers. This study shows that the reduction of the STZ nucleation energy, which is correlated with the free volume increase, brings about the post-yield primary softening of the amorphous polymers up to the steady-state strain value; and the secondary hardening is a result of the increased number density of the STZs, which is required for large plastic strains, while their nucleation energy is stabilized beyond the steady-state strain. The evolutions of the free volume content and STZ nucleation energy are also used to demonstrate the effect of the strain rate, temperature, and thermal history of the sample on its post-yield behavior. The obtained results from the model are compared with the experimental observations on poly(methyl methacrylate) which show a satisfactory consonance.
Increasing local density and purity of molecules/bacteria on a sensing surface from diluted blood using 3D hybrid electrokinetics
Authors: Cheng I-Fang , Chen Tzu-Ying , Chao Wen-Cheng
Published: June 2016

We present a long-range and selective nanocolloid/molecular/bacteria concentrator based on 3D hybrid AC electrokinetics (ACEK) that includes AC dielectrophoresis (DEP) and biased AC electroosmosis (ACEO). Through a convergency comb-shaped electrode design, this long-range ACEO allows the effective transport of a high number of targets into the centre of the detection zone. In the proposed 3D hybrid electrokinetics model, 3D ACEO provides long-range transportation, and the 3D DEP provides an effective separation mechanism. Thus, detection targets ranging from nanoscale to micrometers could be selectively concentrated long-range from diluted blood. The proposed design was used for selectively concentrating nanocolloids and bacteria in the diluted blood sample, respectively. Compared to a 3D short-range dipolar electrode configuration, the detection limit of long-range 3D convergency tripolar electrode configuration is one order of magnitude higher. The result also shows that the 3D hybrid ACEK demonstrated a higher purity of any plane above the electrode, which compared positively to the same design of a 2D hybrid ACEK. The concentration factor of the proposed 3D hybrid electrokinetics device increased by several orders of local density and raised the local purity at least 6 orders (from 0.05% to greater than 99.9%). The chip is capable of making a DNA/protein/bacterial aggregate characterized by high local density and purity for further molecular and bacteria detection/analysis.
Student-led microfluidics lab practicals: Improving engagement and learning outcomes
Authors: Morton J. A. S. , Bridle H.
Published: June 2016

Microfluidics has shown rapid growth in both research and development and offers significant commercialisation potential for biomedical and diagnostic applications in particular. However, there is a lack of awareness of microfluidics outside the field of study, and few dedicated educational programmes are available. While many topics incorporate microfluidics teaching, reported initiatives in the literature have not yet taken a problem based learning (PBL) approach to the delivery of practical sessions. The educational approaches already reported typically focus upon production and testing of pre-determined device designs for specific applications, using a “recipe” style of lab teaching. Here, we report on a newly designed lab section of a microfluidic teaching component utilising problem based learning (PBL) to involve the students in all aspects of design, manufacture, and performance characterisation of microfluidic solutions. Details of the lab design and development are given enabling others to replicate the lab structure described here or use it as a basis for the design of similar PBL microfluidics teaching labs. A key focus of the work has been the evaluation of the student experience, and the results of a survey indicate a high degree of student satisfaction and skills development due to the PBL approach.
Capacitance-voltage characteristics of Si and Ge nanomembrane based flexible metal-oxide-semiconductor devices under bending conditions
Authors: Cho Minkyu , Seo Jung-Hun , Park Dong-Wook , Zhou Weidong , Ma Zhenqiang
Published: June 2016

Metal-oxide-semiconductor (MOS) device is the basic building block for field effect transistors (FET). The majority of thin-film transistors (TFTs) are FETs. When MOSFET are mechanically bent, the MOS structure will be inevitably subject to mechanical strain. In this paper, flexible MOS devices using single crystalline Silicon (Si) and Germanium (Ge) nanomembranes (NM) with SiO2, SiO, and Al2O3 dielectric layers are fabricated on a plastic substrate. The relationships between semiconductor nanomembranes and various oxide materials are carefully investigated under tensile/compressive strain. The flatband voltage, threshold voltage, and effective charge density in various MOS combinations revealed that Si NM−SiO2 configuration shows the best interface charge behavior, while Ge NM−Al2O3 shows the worst. This investigation of flexible MOS devices can help us understand the impact of charges in the active region of the flexible TFTs and capacitance changes under the tensile/compressive strains on the change in electrical characteristics in flexible NM based TFTs.