bluuebunny/crossref_metadata_2025 huggingface dataset:
ON FINITE p-GROUPS WITH ABELIAN AUTOMORPHISM GROUP
Authors: JAIN VIVEK K. , RAI PRADEEP K. , YADAV MANOJ K.
Published: April 2013

We construct, for the first time, various types of specific non-special finite p-groups having abelian automorphism group. More specifically, we construct groups G with abelian automorphism group such that γ2(G) < Z(G) < Φ(G), where γ2(G), Z(G) and Φ(G) denote the commutator subgroup, the center and the Frattini subgroup of G respectively. For a finite p-group G with elementary abelian automorphism group, we show that at least one of the following two conditions holds true: (i) Z(G) = Φ(G) is elementary abelian; (ii) γ2(G) = Φ(G) is elementary abelian, where p is an odd prime. We construct examples to show the existence of groups G with elementary abelian automorphism group for which exactly one of the above two conditions holds true.
PLATE BUCKLING ANALYSIS USING A GENERAL HIGHER-ORDER SHEAR DEFORMATION THEORY
Authors: CHALLAMEL NOËL , KOLVIK GJERMUND , HELLESLAND JOSTEIN
Published: April 2013

The buckling of higher-order shear plates is studied in this paper with a unified formalism. It is shown that usual higher-order shear plate models can be classified as gradient elasticity Mindlin plate models, by augmenting the constitutive law with the shear strain gradient. These equivalences are useful for a hierarchical classification of usual plate theories comprising Kirchhoff plate theory, Mindlin plate theory and third-order shear plate theories. The same conclusions were derived by Challamel [Mech. Res. Commun.38 (2011) 388] for higher-order shear beam models. A consistent variational presentation is derived for all generic plate theories, leading to meaningful buckling solutions. In particular, the variationally-based boundary conditions are obtained for general loading configurations. The buckling of the isotropic or orthotropic composite plates is then investigated analytically for simply supported plates under uniaxial or hydrostatic in-plane loading. An analytical buckling formula is derived that is common to all higher-order shear plate models. It is shown that cubic-based interpolation models for the displacement field are kinematically equivalent, and lead to the same buckling load results. This conclusion concerns for instance the plate models of Reddy [J. Appl. Mech.51 (1984) 745] or the one of Shi [Int. J. Solids Struct.44 (2007) 4299] even though these models are statically distinct (leading to different stress calculations along the cross-section). Finally, a numerical sensitivity study is made.
FINITELY GENERATED NIL BUT NOT NILPOTENT EVOLUTION ALGEBRAS
Authors: TIAN JIANJUN PAUL , ZOU YI MING
Published: April 2013

To use evolution algebras to model population dynamics that both allow extinction and introduction of certain gametes in finite generations, nilpotency must be built into the algebraic structures of these algebras with the entire algebras not to be nilpotent if the populations are assumed to evolve for a long period of time. To adequately address this need, evolution algebras over rings with nilpotent elements must be considered instead of evolution algebras over fields. This paper develops some criteria, which are computational in nature, about the nilpotency of these algebras, and shows how to construct finitely generated evolution algebras which are nil but not nilpotent.
MULTIPLICATION GROUPS AND INNER MAPPING GROUPS OF CAYLEY–DICKSON LOOPS
Authors: KIRSHTEIN JENYA
Published: April 2013

The Cayley–Dickson loop Qn is the multiplicative closure of basic elements of the algebra constructed by n applications of the Cayley–Dickson doubling process (the first few examples of such algebras are real numbers, complex numbers, quaternions, octonions, sedenions). We establish that the inner mapping group Inn (Qn) is an elementary abelian 2-group of order 22n-2 and describe the multiplication group Mlt (Qn) as a semidirect product of Inn (Qn) × ℤ2 and an elementary abelian 2-group of order 2n. We prove that one-sided inner mapping groups Inn l(Qn) and Inn r(Qn) are equal, elementary abelian 2-groups of order 22n-1-1. We establish that one-sided multiplication groups Mlt l(Qn) and Mlt r(Qn) are isomorphic, and show that Mlt l(Qn) is a semidirect product of Inn l(Qn) × ℤ2 and an elementary abelian 2-group of order 2n.
SELF-CONSISTENT MEAN FIELD MODEL OF HYDROGEL AND ITS NUMERICAL SIMULATION
Authors: YUAN CHAOHUI , ZHANG HUI
Published: April 2013

A model to describe the micro-structure of macromolecular microsphere composite (MMC) hydrogel is proposed in the framework of self-consistent mean field theory (SCMFT),1 which is usually used to investigate copolymer. Based on the SCMFT approximation, a system of equations associated with the complex topology of MMC hydrogel is derived and solved by a new kind of relaxation algorithm successfully. From the numerical simulation of the model, we find that the two model parameters play important roles in describing the micro-structure of MMC hydrogel, the interactions between two species (polymer chains and MMS spheres) and the volume fraction of MMS spheres. The role of other model parameters on the structure of the MMC hydrogel is also discussed. The numerical results are consistent with the observation from the chemical experiments. Moreover, we also show some new micro-structures obtained by using the SCMFT model, but discovered in chemical experiments.
SYNTHESIS OF STABLE DISPERSIONS OF WATER-SOLUBLE AND SERS-ACTIVE SILVER NANOPARTICLES USING PAM
Authors: XIONG JING , XUE QUNJI , WU XUEDONG
Published: April 2013

Water-soluble and stable dispersions of silver nanoparticles (Ag NPs) were obtained using a straightforward one-step synthesis method. Polyacrylamide (PAM), a kind of water-soluble polymer with polar amide group, is used as stabilizing agent to prevent the aggregation of Ag NPs in aqueous medium. The successful formation of PAM-stabilized Ag NPs was demonstrated by ultraviolet-visible spectroscopy (UV-Vis), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS) and Fourier-transform infrared spectroscopy (FTIR). In addition, the SERS-active substrate made of Ag NPs was fabricated to enhance the Raman signal of R6G and graphene. The significant SERS effective makes the as-synthesized substrate to be widely used in practical applications for routine SERS analysis and water environment biological monitoring.
ENSEMBLE EMPIRICAL MODE DECOMPOSITION WITH SUPERVISED CLUSTER ANALYSIS
Authors: KUO CHIH-YU , WEI SHAO-KUAN , TSAI PI-WEN
Published: April 2013

Ensemble empirical mode decomposition (EEMD) is a noise-assisted data analysis method which decomposes a signal into a collection of intrinsic mode functions (IMFs). There nevertheless appears a multi-mode problem where signals with a similar timescale are decomposed into different IMF components. A possible solution to this problem is to recombine the multi-mode IMF components into a proper single mode but as of yet, no general rules have been proposed in the literature. This paper presents the incorporation of a statistical cluster analysis to assist in the diagnosis of multi-mode IMFs and to recombine them based on the classified clusters. As a result, signals are reorganized into a condensed set of clustered intrinsic mode functions (CIMFs). The method is applied to two sets of artificially synthesized signals and two sets of practical signals: wind turbine noise and earthquake motion. These applications demonstrate that, with the additional cluster analysis, the multi-mode problem can be largely eliminated in a statistically reliable manner, and in situ applications can be improved.
High-level change detection in RDF(S) KBs
Authors: Papavasileiou Vicky , Flouris Giorgos , Fundulaki Irini , Kotzinos Dimitris , Christophides Vassilis
Published: April 2013

With the increasing use of Web 2.0 to create, disseminate, and consume large volumes of data, more and more information is published and becomes available for potential data consumers, that is, applications/services, individual users and communities, outside their production site. The most representative example of this trend is Linked Open Data (LOD), a set of interlinked data and knowledge bases. The main challenge in this context is data governance within loosely coordinated organizations that are publishing added-value interlinked data on the Web, bringing together issues related to data management and data quality, in order to support the full lifecycle of data production, consumption, and management. In this article, we are interested in curation issues for RDF(S) data, which is the default data model for LOD. In particular, we are addressing change management for RDF(S) data maintained by large communities (scientists, librarians, etc.) which act as curators to ensure high quality of data. Such curated Knowledge Bases (KBs) are constantly evolving for various reasons, such as the inclusion of new experimental evidence or observations, or the correction of erroneous conceptualizations. Managing such changes poses several research problems, including the problem of detecting the changes (delta) between versions of the same KB developed and maintained by different groups of curators, a crucial task for assisting them in understanding the involved changes. This becomes all the more important as curated KBs are interconnected (through copying or referencing) and thus changes need to be propagated from one KB to another either within or across communities. This article addresses this problem by proposing a change language which allows the formulation of
concise
and
intuitive
deltas. The language is expressive enough to
describe unambiguously
any possible change encountered in curated KBs expressed in RDF(S), and can be
efficiently and deterministically detected
in an automated way. Moreover, we devise a change detection
algorithm
which is sound and complete with respect to the aforementioned language, and study appropriate
semantics for executing the deltas
expressed in our language in order to move backwards and forwards in a multiversion repository, using only the corresponding deltas. Finally, we evaluate through experiments the effectiveness and efficiency of our algorithms using real ontologies from the cultural, bioinformatics, and entertainment domains.
Schema matching and embedded value mapping for databases with opaque column names and mixed continuous and discrete-valued data fields
Authors: Jaiswal Anuj , Miller David J. , Mitra Prasenjit
Published: April 2013

Schema matching and value mapping across two information sources, such as databases, are critical information aggregation tasks. Before data can be integrated from multiple tables, the columns and values within the tables must be matched. The complexities of both these problems grow quickly with the number of attributes to be matched and due to multiple semantics of data values. Traditional research has mostly tackled schema matching and value mapping independently, and for categorical (discrete-valued) attributes. We propose novel methods that leverage value mappings to enhance schema matching in the presence of opaque column names for schemas consisting of both continuous and discrete-valued attributes. An additional source of complexity is that a discrete-valued attribute in one schema could in fact be a quantized, encoded version of a continuous-valued attribute in the other schema. In our approach, which can tackle both “onto” and bijective schema matching, the fitness objective for matching a pair of attributes from two schemas exploits the statistical distribution over values within the two attributes. Suitable fitness objectives are based on Euclidean-distance and the data log-likelihood, both of which are applied in our experimental study. A heuristic local descent optimization strategy that uses two-opt switching to optimize attribute matches, while simultaneously embedding value mappings, is applied for our matching methods. Our experiments show that the proposed techniques matched mixed continuous and discrete-valued attribute schemas with high accuracy and, thus, should be a useful addition to a framework of (semi) automated tools for data alignment.
Observing SQL queries in their natural habitat
Authors: Grust Torsten , Rittinger Jan
Published: April 2013

We describe H
abitat
, a declarative observational debugger for SQL. H
abitat
facilitates true language-level (not: plan-level) debugging of, probably flawed, SQL queries that yield unexpected results. Users mark SQL subexpressions of arbitrary size and then observe whether these evaluate as expected. H
abitat
understands query nesting and free row variables in correlated subqueries, and generally aims to not constrain users while suspect subexpressions are marked for observation.

From the marked SQL text, H
abitat
's algebraic compiler derives a new query whose result represents the values of the desired observations. These observations are generated by the target SQL database host itself and are derived from the original data: H
abitat
does not require prior data extraction or extra debugging middleware. Experiments with TPC-H database instances indicate that observations impose a runtime overhead sufficiently low to allow for interactive debugging sessions.
ElasTraS
Authors: Das Sudipto , Agrawal Divyakant , El Abbadi Amr
Published: April 2013

A
database management system
(DBMS) serving a cloud platform must handle large numbers of application databases (or
tenants
) that are characterized by diverse schemas, varying footprints, and unpredictable load patterns. Scaling out using clusters of commodity servers and sharing resources among tenants (i.e.,
multitenancy
) are important features of such systems. Moreover, when deployed on a pay-per-use infrastructure, minimizing the system's operating cost while ensuring good performance is also an important goal. Traditional DBMSs were not designed for such scenarios and hence do not possess the mentioned features critical for DBMSs in the cloud.

We present ElasTraS, which combines three design principles to build an elastically-scalable multitenant DBMS for transaction processing workloads. These design principles are gleaned from a careful analysis of the years of research in building scalable key-value stores and decades of research in high performance transaction processing systems. ElasTraS scales to thousands of tenants, effectively consolidates tenants with small footprints while scaling-out large tenants across multiple servers in a cluster. ElasTraS also supports
low-latency multistep ACID transactions
, is fault-tolerant, self-managing, and highly available to support mission critical applications. ElasTraS leverages Albatross, a low overhead on-demand
live database migration
technique, for elastic load balancing by adding more servers during high load and consolidating to fewer servers during usage troughs. This elastic scaling minimizes the operating cost and ensures good performance even in the presence of unpredictable changes to the workload.

We elucidate the design principles, explain the architecture, describe a prototype implementation, present the detailed design and implementation of Albatross, and experimentally evaluate the implementation using a variety of transaction processing workloads. On a cluster of 20 commodity servers, our prototype serves thousands of tenants and serves more than 1 billion transactions per day while migrating tenant databases with minimal overhead to allow lightweight elastic scaling. Using a cluster of 30 commodity servers, ElasTraS can scale-out a terabyte TPC-C database serving an aggregate throughput of approximately one quarter of a million TPC-C transactions per minute.
Moving spatial keyword queries
Authors: Wu Dingming , Yiu Man Lung , Jensen Christian S.
Published: April 2013

Web users and content are increasingly being geo-positioned. This development gives prominence to spatial keyword queries, which involve both the locations and textual descriptions of content. We study the efficient processing of continuously moving top-kspatial keyword (MkSK) queries over spatial text data. State-of-the-art solutions for moving queries employsafe zonesthat guarantee the validity of reported results as long as the user remains within the safe zone associated with a result. However, existing safe-zone methods focus solely on spatial locations and ignore text relevancy.

We propose two algorithms for computing safe zones that guarantee correct results at any time and that aim to optimize the server-side computation as well as the communication between the server and the client. We exploit tight and conservative approximations of safe zones and aggressive computational space pruning. We present techniques that aim to compute the next safe zone efficiently, and we present two types of conservative safe zones that aim to reduce the communication cost. Empirical studies with real data suggest that the proposals are efficient.

To understand the effectiveness of the proposed safe zones, we study analytically the expected area of a safe zone, which indicates on average for how long a safe zone remains valid, and we study the expected number of influence objects needed to define a safe zone, which gives an estimate of the average communication cost. The analytical modeling is validated through empirical studies.
Phrase detectives
Authors: Poesio Massimo , Chamberlain Jon , Kruschwitz Udo , Robaldo Livio , Ducceschi Luca
Published: April 2013

We are witnessing a paradigm shift in Human Language Technology (HLT) that may well have an impact on the field comparable to the statistical revolution: acquiring large-scale resources by exploiting collective intelligence. An illustration of this new approach is
Phrase Detectives
, an interactive online
game with a purpose
for creating anaphorically annotated resources that makes use of a highly distributed population of contributors with different levels of expertise.

The purpose of this article is to first of all give an overview of all aspects of Phrase Detectives, from the design of the game and the HLT methods we used to the results we have obtained so far. It furthermore summarizes the lessons that we have learned in developing this game which should help other researchers to design and implement similar games.
Robust convention emergence in social networks through self-reinforcing structures dissolution
Authors: Villatoro Daniel , Sabater-Mir Jordi , Sen Sandip
Published: April 2013

Convention emergence solves the problem of choosing, in a decentralized way and among all equally beneficial conventions, the same convention for the entire population in the system for their own benefit. Our previous work has shown that reaching 100% agreement is not as straighforward as assumed by previous researchers, that, in order to save computational resources fixed the convergence rate to 90% (measuring the time it takes for 90% of the population to coordinate on the same action). In this article we present the notion of social instruments as a set of mechanisms that facilitate and accelerate the emergence of norms from repeated interactions between members of a society, only accessing local and public information and thus ensuring agents' privacy and anonymity. Specifically, we focus on two social instruments: rewiring and observation. Our main goal is to provide agents with tools that allow them to leverage their social network of interactions while effectively addressing coordination and learning problems, paying special attention to dissolving metastable subconventions.

The first experimental results show that even with the usage of the proposed instruments, convergence is not accelerated or even obtained in irregular networks. This result leads us to perform an exhaustive analysis of irregular networks discovering what we have defined as
Self-Reinforcing Structures
(SRS). The SRS are topological configurations of nodes that promote the establishment and persistence of subconventions by producing a continuous reinforcing effect on the frontier agents. Finally, we propose a more sophisticated composed social instrument (observation + rewiring) for robust resolution of
subconventions
, which works by the dissolution of the stable frontiers caused by the Self-Reinforcing Substructures (SRS) within the social network.
Convergence results for ant routing algorithms via stochastic approximation
Authors: Purkayastha Punyaslok , Baras John S.
Published: April 2013

In this article, we provide convergence results for an Ant-based Routing Algorithm (ARA) for wireline, packet-switched communication networks, that are acyclic. Such algorithms are inspired by the foraging behavior of ants in nature. We consider an ARA algorithm proposed earlier by Bean and Costa [2005]. The algorithm has the virtues of being adaptive and distributed, and can provide a multipath routing solution. We consider a scenario where there are multiple incoming data traffic streams that are to be routed to their respective destinations via the network. Ant packets, which are nothing but probe packets, are introduced to estimate the path delays in the network. The node routing tables, which consist of routing probabilities for the outgoing links, are updated based on these delay estimates. In contrast to the available analytical studies in the literature, the link delays in our model are stochastic, time-varying, and dependent on the link traffic. The evolution of the delay estimates and the routing probabilities are described by a set of stochastic iterative equations. In doing so, we take into account the distributed and asynchronous nature of the algorithm operation. Using methods from the theory of stochastic approximations, we show that the evolution of the delay estimates can be closely tracked by a deterministic ODE (Ordinary Differential Equation) system, when the step size of the delay estimation scheme is small. We study the equilibrium behavior of the ODE system in order to obtain the equilibrium behavior of the routing algorithm. We also explore properties of the equilibrium routing probabilities, and provide illustrative simulation results.
Learning user preferences for adaptive pervasive environments
Authors: Gallacher Sarah , Papadopoulou Eliza , Taylor Nick K. , Williams M. Howard
Published: April 2013

Personalization mechanisms often employ behavior monitoring and machine learning techniques to aid the user in the creation and management of a preference set that is used to drive the adaptation of environments and resources in line with individual user needs. This article reviews several of the personalization solutions provided to date and proposes two hypotheses: (A) an incremental machine learning approach is better suited to the preference learning problem as opposed to the commonly employed batch learning techniques, (B) temporal data related to the duration that user context states and preference settings endure is a beneficial input to a preference learning solution. These two hypotheses are the cornerstones of the Dynamic Incremental Associative Neural NEtwork (DIANNE) developed as a tailored solution to preference learning in a pervasive environment. DIANNE has been evaluated in two ways: first, by applying it to benchmark datasets to test DIANNE's performance and scalability as a machine learning solution; second, by end-users in live trials to determine the validity of the proposed hypotheses and to evaluate DIANNE's utility as a preference learning solution.
A state-dependent time evolving multi-constraint routing algorithm
Authors: Mellouk Abdelhamid , Hoceini Said , Zeadally Sherali
Published: April 2013

This article proposes a state-dependent routing algorithm based on a global optimization cost function whose parameters are learned from the real-time state of the network with no a priori model. The proposed approach samples, estimates, and builds the model of pertinent and important aspects of the network environment such as type of traffic, QoS policies, resources, etc. It is based on the trial/error paradigm combined with swarm-adaptive approaches. The global system uses a model that combines both a stochastic planned prenavigation for the exploration phase with a deterministic approach for the backward phase. We conducted a performance analysis of the proposed algorithm using OPNET based on several topologies such as the Nippon telephone and telegraph network. The simulation results obtained demonstrate substantial performance improvements over traditional routing approaches as well as the benefits of learning approaches for networks with dynamically changing traffic.
There is more in personal heritage than data
Authors: Petrelli Daniela
Published: April 2013

On Heritage aims to offer and promote a rich discussion at the intersection of art, performance, and culture that expands the boundaries of HCI while broadening our understanding of how things of the past come to matter in the present.

Elisa Giaccardi, Editor
Systemic and meta-systemic laws
Authors: Yáñez Ximena Dávila , Romesín Humberto Maturana
Published: April 2013

Models help bridge the gap between observing and making---especially when systems are involved (as in designing for interaction, service, and evolution). This forum introduces new models, links them to existing models, and describes their histories and why they matter.

Hugh Dubberly, Editor
Cathodic Grafting of Alkyl Chains onto Glassy Carbon Easy Immobilization of Ferrocene Used as Redox Probe
Authors: Jouikov Viatcheslav , Simonet Jacques
Published: April 2013

ω-Iodo- and α,ω-dihaloalkanes, in contact with glassy carbon (GC) at potentials more negative than -1.7 V vs. Ag/AgCl, can be immobilized at the electrode surface. The process, involving cathodic charge of the graphitized zones of GC and formation of nucleophilic sites within the superficial layersl, is typically carried out in an aprotic organic solvent containing tetraalkylammonium salts. With α,ω-dihaloalkanes, the process is completed by a nucleophilic displacement towards pending C-I functions left after the grafting of the first C-I group. The reaction of negatively charged carbon with bis-(ω-iodoalkyl)ferrocenes was successfully used for immobilization of ferrocenyl groups, an efficient redox probe. The levels of surface coverage were shown to be high, with the apparent surface concentrations of ferrocene greater than 10-8 mol cm-2. The alkylferrocene layers deposited onto carbon are chemically and electrochemically stable; these new superficial structures are expected to be suitable for the use in efficient electricity storage devices.
Indirect Electrochemical Cyclisation of Bromoalkoxylated Derivatives Using Environmentally Friendly Methodologies
Authors: Duñach E. , Medeiros M. J. , Olivero S.
Published: April 2013

The electrochemical intramolecular cyclization of bromoalkoxylated derivatives 1 using Ni(II) complex as mediator of electron transfer was carried out in ethanol by constant-current electrolysis in one-compartment cell in the absence of sacrificial anodes as an environmentally friendly systems. It is demonstrated that the electroreduction reaction of bromoalkoxylated derivatives was catalyzed by the electrogenerated Ni(I) complexes. Only cyclization to the five-membered-ring esters was obtained in moderate to good yields as the main products. Functionalyzed tetrahydrofurans are important intermediates in the synthesis of natural products such as lignans. A mechanistic scheme is proposed to explain the results obtained by means of cyclic voltammetry and constant-current electrolysis.
Electrochemical Investigation of Ketone Complexation by Lewis Acids in a Chloroaluminate Ionic Liquid
Authors: Cheek Graham T.
Published: April 2013

A comparative study of 9-fluorenone electrochemistry in the AlCl3 : 1-ethyl-3-methylimidazolium chloride system has been carried out by addition of the Lewis acids AlCl3 and HfCl4 to fluorenone initially in the neutral melt. It has been found that each Lewis acid is capable of forming a complex with fluorenone, resulting in a positive peak potential shift for the reduction process. Neither these peak potentials, nor the colors of the complexes, are exactly the same, indicating that distinct complexes are formed for HfCl4 and AlCl3. There is some possibility of interaction of HfCl4 with the chloroaluminate melt to form the Lewis acid Al2Cl7-, but this route seems to play a minor role in the present case.
Cyclic Voltammetry of Fluorenones: Simulation
Authors: Haque Inam ul , Fatima Muqudis , Tariq Muqaddas
Published: April 2013

Simulation of the cyclic voltammograms of dinitributoxy carbonyl fluorenone, t-butyl-2,4,7-trinitrofluorenone, 4-carboxyl-2,5,7-trinitrofluorenone, and 2,4,7-trinitrofluorenone in DMF\tetra-n-butylammonium perchlorate observed (9) at mercury bead electrode were simulated by using softwares: CVSIM and ESP 2.4. Two cathodic and two anodic peaks were analysed. ESP took less time. In case of 2-alkyl-4,7-dinitrofluorenone, three anodic and two cathodic experimentally (9) reported peaks were analysed by simulation.
Optimization of Electropolymerized Nickel Salen-Based Film for Electro-oxidation of Aldehydes
Authors: Wannaprom Napaporn , Vanalabhpatana Parichatr
Published: April 2013

A glassy carbon electrode modified with poly-nickel hydroxy salen (poly-Ni(OH)salen) film has been developed for the electro-oxidation of aldehydes. This film can be prepared via steps: (i) electropolymerization of N,N'-bis(salicylidene)ethylenediaminonickel(II) or nickel(II) salen solution, followed by (ii) the film transformation in alkaline medium. Cyclic voltammetric results reveal that the poly-Ni(OH)salen film modified electrode can respond to aldehydes, especially acetaldehyde, by giving anodic peak currents for their oxidation. Additionally, parameters affecting the formation and the electrocatalytic performance of the film are discussed.
Electrophoretic Display Driven by Commercially Applicable and All-Solution-Processed Organic Thin-Film Transistors
Authors: Kim Kyung Min , Na Hyungil , Lee Jung Eun , Park Chang Bum , Bae Jong-Uk , Yoo Soon Sung , Yang Myung Su , Kim Chang-Dong , Kang In Byeong , Yeo Sang Deog
Published: April 2013

In this study, we have successfully demonstrated a 6-inch video graphics array (VGA) electrophoretic display (EPD) driven by the all-solution-processed organic thin-film transistors (OTFTs) with industrially applicable sputtering copper electrodes. Except for the sputtering electrodes, all layers of EPD’s backplane were processed via solution processing of organic materials. The all-solution-processed OTFTs with sputtering electrode of copper represent the average field-effect mobility of 0.34cm2/Vs, a threshold voltage of -6.2V, a subthreshold gate swing of 2.3V/dec, and an on-to-off current ratio of ~105. The electrical characteristics of the OTFTs are considerably sufficient for EPD operation, and representing clear operating images.
MEMS Based Mechanical Resonant Push-Pull Scanning Endoscope
Authors: Gu Kebin , Tsui Chi Leung , Wang Wei-Chih
Published: April 2013

Here we present a microfabricated SU-8 cantilever scanner. Current SU-8 rib waveguide design improved the output beam diameter of our previous design from ~50μm to ~5.0μm, further improves our spatial resolution. The proposed rib waveguide design also allows a relatively large waveguide cross section (4μm in height and 55μm in width) and broader wavelength range in single-mode operation (λ= 0.7μm to 1.3μm) with a minimum transmission loss (85% output transmission efficiency with Gaussian beam profile input). Our design also provides a new means to create a 2-D raster scanning pattern using a microfabricated push-pull actuator, verified by a transient finite element analysis (FEA). The scanner's line resolution and field of view (FOV) have been optimized through a parametric study using modal and harmonic analyses. This optical scanner may find application in the area of endoscopy, where there is a need for a minimally invasive device that reduces patient discomfort.
Cardiopulmonary Monitoring Research Based on Noncontact Sensor of Vital Signs
Authors: Hu Wei , Zhao Zhangyan , Wang Yunfeng , Lin Fujiang , Zhang Haiying
Published: April 2013

Microwave Doppler radar has potential to provide a practical tool for noncontact detecting cardiopulmonary movement. In this paper, a noncontact sensor of vital signs was realized based on continuous wave Doppler radar, in addition, real-time signal processing was studied for single target noncontact cardiopulmonary monitoring, including short-time Fourier transform, Sinc interpolation and peak searching. These methods can improve the accuracy, response speed and shorten the latency of cardiopulmonary Doppler radar signal processing considerably, with relatively small amount of calculation.
Design and Implementation of a Soft-Measuring System for High-Temperature Field Based on Color CCD Image Sensor
Authors: Li Yuxiao , Li Sheng , Ye Kuntao
Published: April 2013

The soft-measuring system consists of an optical lens, a color CCD camera, an image acquisition card, a computer and associated measuring software based on colorimetric temperature measurement. Using the system, the temperature distribution of a high-temperature field can be measured and then displayed on the screen. A method of adjusting the intensity of light is developed to expand the range of the measuring temperature of the system, and the calibration experiments through blackbody furnace are adopted to calibrate the soft-measuring system. The errors of the measurement caused by the non-ideal spectrum response of CCD image sensor are corrected. Multi-spectral segmenting is applied on the image of the high-temperature field, thus various high-temperature noises in the color image can be reduced or even eliminated. The experiment indicates the soft-measuring instrumentation meets the high-temperature detecting requirements of industrial production due to its high accuracy and reliability.
InGaAs/InP Single Photon Avalanche Diodes
Authors: Lu Zhiwen , Zheng Xiaoguang , Sun Wenlu , Campbell Joe , Jiang Xudong , Itzler Mark A.
Published: April 2013

We propose and demonstrate balanced detectors to improve the performance of sine wave gated single photon avalanche diodes (SPADs). This technique can realize continuous tuning of the operation frequency for sinusoidal gating of SPADs without incorporating band elimination filters. The dual SPAD circuit is biased in a balanced configuration so that the common mode signals are cancelled, which can improve the system sensitivity as well as suppress afterpulsing. At a laser repetition rate of 1 MHz and temperature of 240 K the dark count rate and photon detection efficiency were 58 kHz and 43%, respectively. The afterpulse probability is lower than a sine wave gated single SPAD. Timing resolution, i.e., jitter, is also reported. A jitter of 240 ps was achieved with 1 photon per pulse and excess bias of 1.6%.
Effect of Cadmium Sulphate Concentrations on CdS Thin Films
Authors: Mahalingam Thaiyan , Dhanasekaran Vikraman , Devadason Suganthi , Ravi Ganesan
Published: April 2013

The various copper sulphate concentrations prepared CdS thin films were coated on glass substrates by chemical bath deposition. The structural, optical, functional group and morphological properties were studied using X-ray diffraction (XRD), UV-Vis-NIR spectrophotometer and scanning electron microscopy, respectively. The deposited films are found to be polycrystalline in nature with hexagonal structure along a (100) preferential orientation plane. The microstructural properties of CdS thin films such as crystallite size, micro strain, texture coefficient and lattice constant were calculated from structural studies and results are compared with earlier reports. The optical properties of CdS thin films band gap were lying between 2.38 and 2.49 eV. The stoichiometric composition with uniform surface morphological properties of the film was obtained in optimized molar concentration. The morphological images revealed that size of the grains was found to be 50 to 75 nm and some place group of grains agglomerate to form larger grains.
Catalytic Synthesis of Carbon Nanotube and Nanofilament Over Oxidized Diamond-Supported Catalysts
Authors: Nakagawa Kiyoharu , Toriyama Takahiro , Tsujino Gai , Ando Toshihiro , Oda Hirokazu
Published: April 2013

Carbon nanotube and filament could be obtained by the decomposition of C2H4 using oxidized diamond-supported metal catalysts with three distinct structural types. Oxidized diamond is proposed as a novel catalytic means for the synthesis of nanocarbons. Oxidized diamond may catalyze unique reactions of importance in carbon nanotube and filament synthesis.
Multiple Auger Decay at Resonant Photo-Excitation in Carbon Thin Films
Authors: Richter Matthias , Paloumpa Ioanna , Friedrich Daniel , Schmeißer Dieter
Published: April 2013

We use resonant photoemission at the C1s edge to study the electronic structure of HOPG, graphene flakes and monolayer graphene. We find remarkable differences in the profile of the Auger decay channels, which we attribute to an additional multiple-Auger with a three-hole final state. A prerequisite for the appearance of this decay mechanism is the existence of localized excitonic states, which cause the appearance of the multiple Auger decay. We use those effects to identify the existence and the quantity of such defect states within the p*-band regime in carbon thin films, because the intensity of the three-hole Auger decay is varying with the defect density of the carbon films. We find that the appearance of the multiple Auger decay is different for multilayer and monolayer graphene. In particular the interaction of impurities leads to broadening of the C1s core levels. The three-hole Auger decay spectroscopy is a new method to detect such contaminations with a high sensitivity.
Effect of Boric Acid on the Nucleation and Growth of Ni Nanoparticles for CNT Growth
Authors: Vanpaemel Johannes , van der Veen Marleen , Huyghebaert Cedric , De Gendt Stefan , Vereecken Philippe M.
Published: April 2013

The effect of boric acid on the electrochemical deposition of nickel nanoparticles is presented in this paper. We show that lowering the concentration of H3BO3 in the electrolyte increases the particle density. At the same time, it was observed that the deposition of nickel stops at an earlier stage when a low concentration of boric acid was used. Both observations can be explained by the formation of an insoluble Ni(OH)2 which was counteracted by the addition of H3BO3. We were able to reduce the current density needed to obtain similar particle densities by almost an order of magnitude.
Cesium Transfer from Granule Conglomerate, Asphalt, and Concrete Using Water Containing Nano-Sized Air Bubbles
Authors: Ueda Yoshiaktsu , Tokuda Yomei , Fujimura Shigeto , Nihei Naoto , Oka Toru
Published: April 2013

Remediation of sites contaminated with radioactive material such as Cs is important because of the risk posed to human health. Here, we report the effectiveness of using water containing air bubbles with a diameter around 100 nm (nanobubbled water) on removal of radioactive Cs. Nanobubbled water was effective for removal of radioactive Cs from granule conglomerate in Fukushima, Japan. Additionally, nanobubbled water made from tap water in Fukushima was also effective for removal of radioactive material from asphalt and concrete, but not wood and marble.
Nitrogenated Ultrananocrystalline Diamond/Amorphous Carbon Composite Films Deposited on Titanium Substrates by Pulsed Laser Deposition
Authors: Al-Riyami Sausan , Yoshitake Tsuyoshi
Published: April 2013

Nitrogenated ultrananocrystalline diamond/nonhydrogenated amorphous carbon composite (UNCD/a-C) films were deposited on titanium in a nitrogen atmosphere by laser pulsed deposition. The adhesion between the films and titanium substrates were remarkably improved as compared with those between hydrogenated (UNCD/a-C) films and titanium substrates. X-ray photoemission and near edge X-ray absorption structure measurements indicated an increase in the sp2 and sp bonding fraction such as C=N double and triple bonds by nitrogenation. Since they locally disconnect tetrahedral bonding in the films and expected to release an internal stress in the films, the film adhesion might be improved.
Understanding Cytotoxicity of Engineered Nanomaterials
Authors: Garde Komal , Crawford Steven , Aravamudhan Shyam
Published: April 2013

The goal of this paper is understand cytotoxicity of different engineered nanomaterials when exposed to different human-relevant cell types. The objective is to address few critical questions in nanotoxicity, namely variation of cytotoxicity with cell type, nanomaterial uptake and cytotoxicity response to varying physiochemical properties. We find that silica nanoparticles to be non-toxic to both cells lines and at the tested doses, while both ZnO nanoparticles and Au nanorods were observed to be toxic at certain doses and time-points. We also observed initial evidence to demonstrate cell penetration and cell wall morphological alterations after Au and ZnO nanoparticles exposure.
Nitrogenation Effects on n-Type Electrical Conductivity of Ultrananocrystalline Diamond/Hydrogenated Amorphous Carbon Composite Films Prepared by Pulsed Laser Deposition
Authors: Al-Riyami Sausan , Setoyama Hiroyuki , Sumitani Kazushi , Hirai Yasuharu , Yoshitake Tsuyoshi
Published: April 2013

Nitrogenated ultrananocrystalline diamond/hydrogenated amorphous carbon composite films were prepared in a hydrogen and nitrogen mixed-gas atmosphere by pulsed laser deposition with graphite targets. The electrical conductivity in n-type conduction remarkably increases to 18 §Ù–1×cm–1 at 300 K with an increase in the nitrogen content up to 7.9 at.%. In the nitrogen content range from 7.9 to 10.4 at.%, the electrical conductivity is suddenly and dramatically decreased down to 0.03 §Ù–1·cm–1 in reverse, accompanied by the disappearance of diamond grains in the films. A huge number of grain boundaries owing to the existence of diamond grains embedded in UNCD/a-C:H films, which is structural specific to UNCD/a-C:H, should play a significant role in the large electrical conductivity enhancement by nitrogen doping. The X-ray photoemission and near-edge X-ray fine-absorption spectroscopic measurements could not detect an evident difference in the spectra that explain the sudden irregular change in the electrical conductivity.
Electrochemical Discrimination of Ascorbic Acid Diastereomers Using Dihydroxyalkanedithiol-modified Au Electrode
Authors: Komatsu Masaharu , Ando Takahiro , Suzuki Shota
Published: April 2013

L-ascorbic acid (AA) and D-isoascorbic acid (IA) are diastereomer each other. Oxidation current responses of AA and IA in aqueous electrolyte solution containing both AA and IA might be successfully observed as two separated anodic peaks from AA and IA, using asymmetric carbon-linked thiol derivative-modified Au electrodes. These two separated peaks appeared when the modified electrode might be experienced with oxidation adsorption-desorption.
Through the Looking Glass: A Journey into Innovation
Authors: Jalan Radha
Published: April 2013

Innovations are the lifeblood of technical companies. It provides an edge in competitiveness, market penetration, builds a reputation for being technically at the cutting edge, and finally brings financial rewards. Real success though depends not only on innovation but along with it also on communication and resources. ElectroChem, Inc., a leading company in hydrogen and fuel cell technologies founded in 1986, lost its founder, and technical wizard in 1992. ElectroChem’s survival and its growth, has depended on its reinterpretation of the word innovation in a unique way.
A Novel Technique to Quantify Micro Insulation Defects on Grain-Oriented Electrical Steel Coating Using the Scanning Vibrating Electrode Technique
Authors: Cassemis Lance Thomas Liam , Sullivan James H. , Power Dominic
Published: April 2013

Electrical steels are a specialised group of low carbon silicon steel alloys widely used in transformers, generators and motors. It has been previously shown that reducing eddy currents by insulating laminations in an iron core significantly increases efficiency. During production electrical steels are initially coated with magnesium oxide (MgO) slurry that reacts with the silicon in the upper surface of the substrate during annealing to produce a magnesium silicate called forsterite. The material receives a phosphate based secondary coating which helps to ensure the material is fully insulated and improves magnetic properties by adding tension to the material. Until now industrial measurements of resistance have been conducted using copper probes on a Franklin tester to give an average resistance of the area but small defects such as pin holes commonly average out to produce infinite resistance insulation. A novel method of using a Scanning Vibrating Electrode Technique (SVET) has enabled high resolution results of over 6500 times greater than the conventional industrial method used. The SVET is an electrochemical method traditionally used to resolve and quantify localised corrosion currents at the surface of a metal submerged in an electrolyte. This novel technique works by submerging samples with defects into 0.1% NaCl electrolyte. A 1µA current is passed through a sample that has an insulation coating. The SVET can detect regions where insulation has failed or is thin. Testing has been conducted on samples High permeability substrate with just forsterite coating, just phosphate coating, both coatings and both coatings with defects.
Cyclic Voltammetry of Zn/Zn(II) Couple in Dycyanamide Anion and Bis-(trifluoromethylsulfonyl)Imide Anion Based Ionic Liquids
Authors: Xu Min , Ivey Douglas G. , Qu Wei , Xie Zhong , Bing Yonghong
Published: April 2013

The electrochemistry of a Zn/Zn(II) couple was studied and compared in four kinds of room temperature ionic liquids (RTILs) (1-butyl-1-methylpyrrolidinium dicyanamide (BMP-DCA), 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide (EMI-TFSI), 1-butyl-1-methylpyrrolidinium bis(trifluoromethanesulfonyl)imide (BMP-TFSI) and 1-methyl-1-pentylpyrrolidinium bis(trifluoromethanesulfonyl)imide (MPP-TFSI)), with the aim of screening desirable RTILs as replacements for traditional aqueous electrolytes for Zn rechargeable batteries. Cyclic voltammetry was used to study the reversibility and cyclability of Zn redox in each RTIL. The morphology of Zn deposits prepared from each RTIL was characterized by scanning electron microscopy. The results show that Zn redox has the best cyclability in the DCA-based RTIL, with the Zn deposit morphology characterized by finely dispersed rods composed of granular Zn particles (~50-100 nm in size). In TFSI-based ionic liquids, the Zn/Zn(II) couple reaction had a higher current density than that in the DCA-based ionic liquid, implying different electron transfer processes. BMP-DCA and EMI-TFSI are promising RTILs worthy of further investigation.
Inhibiting Ability of Chelating Agent on Aluminum Corrosion in Alkaline Solution
Authors: Wu Chun-Hsing , Chung Chia-Chun , Hsueh Kan-Lin , Chang Wen-Chen
Published: April 2013

A prototype aluminum air battery containing 4 cells connected inseries was tested. This battery was discharged with a 3-LED flashlight. It lasted 29.6 hours before voltage dropped below 2.7 V. Anenergy density of 350 Wh/kg could be achieved. The polarizationcurves of 0.5 M KOH and 4.0 M KOH electrolyte of a single cellwith different amount of electrolytes were measured. Cell with 4.0M KOH was out performance than 0.5 M KOH. 6-layerelectrolyte was better than 2-layer electrolyte due to electrolytedrying out due to hydrogen evolution.