Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

Technological University Dublin

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 601 - 630 of 2383

Full-Text Articles in Physical Sciences and Mathematics

Intense Mid-Infrared Emission At 3.9 Μm In Ho3+-Doped Zbya Glasses For Potential Use As A Fiber Laser, Haiyan Zhao, Ruicong Wang, Xin Wang, Shijie Jia, Yaxian Fan, Elfed Lewis, Gerald Farrell, Shunbin Wang, Pengfei Wang Jan 2020

Intense Mid-Infrared Emission At 3.9 Μm In Ho3+-Doped Zbya Glasses For Potential Use As A Fiber Laser, Haiyan Zhao, Ruicong Wang, Xin Wang, Shijie Jia, Yaxian Fan, Elfed Lewis, Gerald Farrell, Shunbin Wang, Pengfei Wang

Articles

Intense mid-infrared emission at 3.9 µm in Ho3+-doped ZBYA glasses with direct upper laser level (Ho3+ : 5 I5) pumping at a wavelength of 888 nm is reported for the first time, to the best of our knowledge. Spectroscopic parameters were determined using the Judd–Ofelt theory and the measured absorption spectrum. The maximum emission cross section of the Ho3+-doped ZBYA glass is estimated to be 2.7 × 10−21 cm2 at 3906 nm. Additionally, fluorescence spectra and lifetimes of ZBYA glasses with different Ho3+ ion doping concentrations were measured. The results provide theoretical and experimental basis for better selection of rare-earth-doped …

Go to article

An Evaluation Of Text Representation Techniques For Fake News Detection Using: Tf-Idf, Word Embeddings, Sentence Embeddings With Linear Support Vector Machine., Sangita Sriram Jan 2020

An Evaluation Of Text Representation Techniques For Fake News Detection Using: Tf-Idf, Word Embeddings, Sentence Embeddings With Linear Support Vector Machine., Sangita Sriram

Dissertations

In a world where anybody can share their views, opinions and make it sound like these are facts about the current situation of the world, Fake News poses a huge threat especially to the reputation of people with high stature and to organizations. In the political world, this could lead to opposition parties making use of this opportunity to gain popularity in their elections. In the medical world, a fake scandalous message about a medicine giving side effects, hospital treatment gone wrong or even a false message against a practicing doctor could become a big menace to everyone involved in …

Go to article

Drug Reviews: Cross-Condition And Cross-Source Analysis By Review Quantification Using Regional Cnn-Lstm Models, Ajith Mathew Thoomkuzhy Jan 2020

Drug Reviews: Cross-Condition And Cross-Source Analysis By Review Quantification Using Regional Cnn-Lstm Models, Ajith Mathew Thoomkuzhy

Dissertations

Pharmaceutical drugs are usually rated by customers or patients (i.e. in a scale from 1 to 10). Often, they also give reviews or comments on the drug and its side effects. It is desirable to quantify the reviews to help analyze drug favorability in the market, in the absence of ratings. Since these reviews are in the form of text, we should use lexical methods for the analysis. The intent of this study was two-fold: First, to understand how better the efficiency will be if CNN-LSTM models are used to predict ratings or sentiment from reviews. These models are known …

Go to article

New Estimates For The Number Of Integer Polynomials With Given Discriminants, Natalia Budarina, Vasilii Bernik, Hugh O'Donnell Jan 2020

New Estimates For The Number Of Integer Polynomials With Given Discriminants, Natalia Budarina, Vasilii Bernik, Hugh O'Donnell

Articles

In this paper, we propose a new method of upper bounds for the number of integer polynomials of the fourth degree with a given discriminant. By direct calculation similar results were established by H. Davenport and D. Kaliada for polynomials of second and third degrees.

Go to article

Advancement Of Predictive Modeling Of Zeta Potentials (Ζ) In Metal Oxide Nanoparticles With Correlation Intensity Index (Cii), Andrey A. Toropov, Natalia Sizochenko, Alla P. Toropova, Danuta Leszczynska, Jerzy Leszczynski Jan 2020

Advancement Of Predictive Modeling Of Zeta Potentials (Ζ) In Metal Oxide Nanoparticles With Correlation Intensity Index (Cii), Andrey A. Toropov, Natalia Sizochenko, Alla P. Toropova, Danuta Leszczynska, Jerzy Leszczynski

Articles

It was expected that index of the ideality of correlation (IIC) and correlation intensity index (CII) could be used as possible tools to improve the predictive power of the quantitative model for zeta potential of nanoparticles. In this paper, we test how the statistical quality of quantitative structure-activity models for zeta potentials (ζ, a common measurement that reflects surface charge and stability of nanomaterial) could be improved with the use of these two indexes. Our hypothesis was tested using the benchmark data set that consists of 87 measurements of zeta potentials in water. We used quasi-SMILES molecular representation to take …

Go to article

Holographic Security, Vincent Toal Jan 2020

Holographic Security, Vincent Toal

Books/Book Chapters

This chapter is concerned with the security applications of holographic techniques. Holograms are used in product authentication, product branding and brand protection, and personal and other documents. Serialization to ensure the uniqueness of each hologram for added security is briefly discussed. The theory of optical character recognition and joint transform correlation methods is outlined. Holographic recording using encrypted reference waves enables secure storage of information. Several methods are considered for encrypting optical data as well as holographic recording of encrypted images and their reconstruction and decryption. Millimeter and microwave holographic imaging techniques for the detection of hidden contraband, narcotics, firearms, …

Go to article

Gmdh-Based Models For Mid-Term Forecast Of Cryptocurrencies (On Example Of Waves), Pavel Mogilev, Anna Boldyreva, Mikhail Alexandrov, John Cardiff Jan 2020

Gmdh-Based Models For Mid-Term Forecast Of Cryptocurrencies (On Example Of Waves), Pavel Mogilev, Anna Boldyreva, Mikhail Alexandrov, John Cardiff

Conference Papers

Cryptocurrencies became one of the main trends in modern economy. However by the moment the forecast of cryptocurrencies values is an open problem, which is almost non-reflected in publications related to finance market. Reasons consist in its novelty, large volatility and its strong dependence on subjective factors. In this experimental research we show possibilities of GMDH-technology to give weekly and monthly forecast for values of cryptocurrency 'Waves' (waves/euro rate). The source information is week data covering the period 2017-2019. We tests 4 algorithms from the GMDH Shell platform on the whole period and on the crisis period 4-th quarter 2017 …

Go to article

Optimisation Of The Performance Of Holographic Beam-Shaping Diffractive Diffusers Through Refinement Of The Recording Process, Cara Jones, Suzanne Martin, Sanjay Keshri, Dervil Cody, Kevin Murphy Jan 2020

Optimisation Of The Performance Of Holographic Beam-Shaping Diffractive Diffusers Through Refinement Of The Recording Process, Cara Jones, Suzanne Martin, Sanjay Keshri, Dervil Cody, Kevin Murphy

Conference Papers

Optical diffusers have uses in laser applications and machine vision. Typical fabrication at a commercial level requires master production and the stamping/copying of individual elements at scale. This expensive, indirect process inhibits custom diffusers at reasonable cost. Previously the authors published a novel, direct, single beam method of recording customizable and controllable volume holographic diffusers by manipulating laser speckle and recording the pattern in photopolymer. This method allows for beam-shaping to produce diffusion patterns of various sizes and shapes. In this work, the direct method of recording controllable holographic diffusers is refined to improve diffuser performance (i.e., a decrease in …

Go to article

Local Alignment Of Frame Of Reference Assignment In English And Swedish Dialogue, Simon Dobnik, John D. Kelleher, Christine Howes Jan 2020

Local Alignment Of Frame Of Reference Assignment In English And Swedish Dialogue, Simon Dobnik, John D. Kelleher, Christine Howes

Conference papers

In this paper we examine how people assign, interpret, negotiate and repair the frame of reference (FoR) in online text-based dialogues discussing spatial scenes in English and Swedish. We describe our corpus and data collection which involves a coordination experiment in which dyadic dialogue participants have to identify differences in their picture of a visual scene. As their perspectives of the scene are different, they must coordinate their FoRs in order to complete the task. Results show that participants do not align on a global FoR, but tend to align locally, for sub-portions (or particular conversational games) in the dialogue. …

Go to article

September 2019 Therapeutic Delivery Update, Elaine Harris Jan 2020

September 2019 Therapeutic Delivery Update, Elaine Harris

Articles

No abstract provided.

Go to article

Determination Of Upconversion Quantum Yields Using Charge-Transfer State Fluorescence Of Heavy-Atom-Free Sensitizer As A Self-Reference, Natalia Kiseleva, Dmitry Busko, Bryce Richards, Mikhail Filatov, Andrey Turshatov Jan 2020

Determination Of Upconversion Quantum Yields Using Charge-Transfer State Fluorescence Of Heavy-Atom-Free Sensitizer As A Self-Reference, Natalia Kiseleva, Dmitry Busko, Bryce Richards, Mikhail Filatov, Andrey Turshatov

Articles

The efficiency of photon upconversion via triplet–triplet annihilation is characterized by an upconversion quantum yield (ΦUC); however, uncertainties remain for its determination. Here, we present a new approach for the relative measurement of ΦUC for green-to-blue upconversion using BODIPY–pyrene donor–acceptor dyad (BD1) as a heavy-atom-free triplet sensitizer. This new approach exploits broad fluorescence from a charge-transfer (CT) state of BD1, which possesses (i) a significant Stokes shift of 181 nm in dichloromethane and (ii) a comparably high CT-fluorescence quantum yield (Φref = 7.0 ± 0.2%), which is independent from oxygen presence and emitter (perylene) concentration while …

Go to article

Microfluidic Flow Direction And Rate Vector Sensor Based On A Partially Gold-Coated Tfbg, Changyu Shen, Dejun Liu, Xiaokang Lian, Tingting Lang, Chunliu Zhao, Yuliya Semenova, Jacques Albert Jan 2020

Microfluidic Flow Direction And Rate Vector Sensor Based On A Partially Gold-Coated Tfbg, Changyu Shen, Dejun Liu, Xiaokang Lian, Tingting Lang, Chunliu Zhao, Yuliya Semenova, Jacques Albert

Articles

In microfluidic chips applications, the monitoring of the rate and the direction of a microfluidic flow is very important. Here, we demonstrate a liquid flow rate and a direction sensor using a partially gold-coated tilted fiber Bragg grating (TFBG) as the sensing element. Wavelength shifts and amplitude changes of the TFBG transmission resonances in the near infrared reveal the direction of the liquid flowing along the fiber axis in the vicinity of the TFBG due to a nanoscale gold layer over part of the TFBG. For a device length of 10 mm (and a diameter of 125 µm for easy …

Go to article

Classification Of The Real Roots Of The Quartic Equation And Their Pythagorean Tunes, Emil Prodanov Jan 2020

Classification Of The Real Roots Of The Quartic Equation And Their Pythagorean Tunes, Emil Prodanov

Articles

Presented is a two-tier analysis of the location of the real roots of the general quartic equation x4+ax3+bx2+cx+d=0 with real coefficients and the classification of the roots in terms of a, b, c, and d, without using any numerical approximations. Associated with the general quartic, there is a number of subsidiary quadratic equations (resolvent quadratic equations) whose roots allow this systematization as well as the determination of the bounds of the individual roots of the quartic. In many cases the root isolation intervals are found. The second tier of the analysis uses two subsidiary cubic equations (auxiliary cubic equations) and …

Go to article

Singlet Oxygen Generation By Porphyrins And Metalloporphyrins Revisited: A Quantitative Structure-Property Relationship (Qspr) Study, Andrey A. Buglak, Mikhail Filatov, Althaf M. Hussain, Manabu Sugimoto Jan 2020

Singlet Oxygen Generation By Porphyrins And Metalloporphyrins Revisited: A Quantitative Structure-Property Relationship (Qspr) Study, Andrey A. Buglak, Mikhail Filatov, Althaf M. Hussain, Manabu Sugimoto

Books/Book chapters

state followed by formation of singlet oxygen (1O2), which is a highly reactive species and mediates various oxidative processes. The design of advanced sensitizers based on porphyrin compounds have attracted significant attention in recent years. However, it is still difficult to predict the efficiency of singlet oxygen generation for a given structure. Our goal was to develop a quantitative structure-property relationship (QSPR) model for the fast virtual screening and prediction of singlet oxygen quantum yields for pophyrins and metalloporphyrins. We performed QSPR analysis of a dataset containing 32 compounds, including various porphyrins and their analogues (chlorins and bacteriochlorins). Quantum-chemical descriptors …

Go to article

Simultaneous Measurement Of Displacement And Temperature Based On Two Cascaded Balloon-Like Bent Fibre Structures, Ke Tian, Ruoning Wang, Meng Zhang, Xiafan Wang, Xin Wang, Guoyong Jin, Elfed Lewis, Gerald Farrell, Pengfei Wang Jan 2020

Simultaneous Measurement Of Displacement And Temperature Based On Two Cascaded Balloon-Like Bent Fibre Structures, Ke Tian, Ruoning Wang, Meng Zhang, Xiafan Wang, Xin Wang, Guoyong Jin, Elfed Lewis, Gerald Farrell, Pengfei Wang

Articles

A low-cost optical fibre sensor based on two cascaded balloon-like bent fibre (BBF) structures for simultaneous displacement and temperature measurement is reported. The sensor is fabricated by cascading two balloon-like bent single-mode fibres (SMFs) which with different bending radii, generating two separate interference dips within a limited wavelength range. The wavelength of the two interference dips exhibits different responses to external displacement and temperature variations, hence simultaneous measurement of displacement and temperature is realized. Experimental results show that the proposed optical fibre sensor achieves a displacement sensitivity of −318.8 pm/μm and a temperature sensitivity of 47.4 pm/°C. Taking advantage of …

Go to article

High-Sensitivity Temperature Sensor Based On Anti-Resonance In High-Index Polymer-Coated Optical Fiber Interferometers, Xiaokang Lian, Qiang Wu, Gerald Farrell, Yuliya Semenova Jan 2020

High-Sensitivity Temperature Sensor Based On Anti-Resonance In High-Index Polymer-Coated Optical Fiber Interferometers, Xiaokang Lian, Qiang Wu, Gerald Farrell, Yuliya Semenova

Articles

Compared to the multimode interference (MMI) effect, the anti-resonance (AR) effect does not rely on the multimode property of the optical waveguide. This Letter shows that fiber bending can suppress the MMI and can break the superposition of AR spectra of multiple modes in a high-index polymer-coated optical fiber interferometer based on a single-mode fiber-polymer-coated no-core fiber-single-mode fiber hetero-structure. This results in the dominance of the AR spectrum of an individual mode and consequently in periodic sharp transmission dips. As a result of this phenomenon and large thermo-optical and thermal expansion coefficients of the polymer, a compact, high-sensitivity and linear …

Go to article

Saperi: Approaching Gender Gap Using Spatial Ability Training Week In High-School Context, Maria Giulia Ballatore, Gavin Duffy, Sheryl Sorby, Anita Tabacco Jan 2020

Saperi: Approaching Gender Gap Using Spatial Ability Training Week In High-School Context, Maria Giulia Ballatore, Gavin Duffy, Sheryl Sorby, Anita Tabacco

Articles

Maria Giulia Ballatore, Gavin Duffy, Sheryl Sorby, and Anita Tabacco. 2020. SAperI: approaching gender gap using Spatial Ability training week in high-school context. In Eighth International Conference on Technological Ecosystems for Enhancing Multiculturality (TEEM’20), October 21–23, 2020, Salamanca, Spain. ACM, New York, NY, USA, 7 pages. https://doi.org/10.1145/3434780.3436577

Go to article

A Collaborative Online Micro: Bit K-12 Teacher Pd Workshop, Roisin Faherty, Karen Nolan, Keith Quille Jan 2020

A Collaborative Online Micro: Bit K-12 Teacher Pd Workshop, Roisin Faherty, Karen Nolan, Keith Quille

Conference Papers

This poster describes the use of online technology to deliver K12 teacher professional development (PD) during the COVID-19 pandemic in Ireland. Traditionally these sessions are delivered in person, with a focus on hand-on activities, but the sudden changes faced by the closures in Ireland required an alternative approach for delivering these sessions. The PD session presented in this poster was a more technically challenging micro:bit workshop, which was delivered online using the micro:bit classroom. This is typically used as an in-class, one to many instructor tool, and trialing this as a PD collaborative tool, was a novel approach. This poster …

Go to article

Poincaré Embeddings In The Task Of Named Entity Recognition, David Muñoz, Fernando Pérez Téllez, David Pinto Jan 2020

Poincaré Embeddings In The Task Of Named Entity Recognition, David Muñoz, Fernando Pérez Téllez, David Pinto

Conference Papers

Hyperbolic embeddings have become important in many natural language processing tasks due to their great ability to capture latent hierarchical data and to encode valuable syntactic and semantic information. We study and consider the ability of Poincaré embeddings to get the most similar nodes to a given node when trying to recognize named entities in a set of text documents. In this paper, we propose a classifier model for the NER (Named Entity Recognition) task by implementing Poincaré embeddings and by using the most frequent n-grams and their Part-of-Speech (POS) structures from the training dataset. We found that POS structures …

Go to article

Volunteered And Crowdsourced Geographic Information: The Openstreetmap Project, Michela Bertolotto, Gavin Mcardle, Bianca Schoen-Phelan Jan 2020

Volunteered And Crowdsourced Geographic Information: The Openstreetmap Project, Michela Bertolotto, Gavin Mcardle, Bianca Schoen-Phelan

Articles

Advancements in technology over the last two decades have changed how spatial data are created and used. In particular, in the last decade, volunteered geographic information (VGI), i.e., the crowdsourcing of geographic information, has revolutionized the spatial domain by shifting the map-making process from the hands of experts to those of any willing contributor. Started in 2004, OpenStreetMap (OSM) is the pinnacle of VGI due to the large number of volunteers involved and the volume of spatial data generated. While the original objective of OSM was to create a free map of the world, its uses have shown how the …

Go to article

Road Network Simplification For Location-Based Services, Abdeltawab Hendawi, John A. Stankovic, Ayman Taha, Shaker El-Sappagh, Amr A. Ahmadain, Mohamed Ali Jan 2020

Road Network Simplification For Location-Based Services, Abdeltawab Hendawi, John A. Stankovic, Ayman Taha, Shaker El-Sappagh, Amr A. Ahmadain, Mohamed Ali

Articles

Road-network data compression or simplification reduces the size of the network to occupy less storage with the aim to fit small form-factor routing devices, mobile devices, or embedded systems. Simplification (a) reduces the storage cost of memory and disks, and (b) reduces the I/O and communication overhead. There are several road network compression techniques proposed in the literature. These techniques are evaluated by their compression ratios. However, none of these techniques takes into consideration the possibility that the generated compressed data can be used directly in Map-matching operation which is an essential component for all location-aware services. Map-matching matches a …

Go to article

Swirling Fluid Flow In Flexible, Expandable Elastic Tubes: Variational Approach, Reductions And Integrability, Rossen Ivanov, Vakhtang Putkaradze Jan 2020

Swirling Fluid Flow In Flexible, Expandable Elastic Tubes: Variational Approach, Reductions And Integrability, Rossen Ivanov, Vakhtang Putkaradze

Articles

Many engineering and physiological applications deal with situations when a fluid is moving in flexible tubes with elastic walls. In real-life applications like blood flow, a swirl in the fluid often plays an important role, presenting an additional complexity not described by previous theoretical models. We present a theory for the dynamics of the interaction between elastic tubes and swirling fluid flow. The equations are derived using a variational principle, with the incompressibility constraint of the fluid giving rise to a pressure-like term. In order to connect this work with the previous literature, we consider the case of inextensible and …

Go to article

Designing A National Blended Learning Program For “Out‑Of‑Field” Mathematics Teacher Professional Development, Merrilyn Goos, John O’Donoghue, Máire Ní Ríordáin, Fiona Faulkner, Tony Hall, Niamh O'Meara Jan 2020

Designing A National Blended Learning Program For “Out‑Of‑Field” Mathematics Teacher Professional Development, Merrilyn Goos, John O’Donoghue, Máire Ní Ríordáin, Fiona Faulkner, Tony Hall, Niamh O'Meara

Articles

“Out-of-field” teaching refers to the practice of assigning secondary school teachers to teach subjects that do not match their training or education. This practice is an issue of concern in many countries around the world, and seems particularly prevalent in the teaching of mathematics. The aim of this paper is to analyse the design principles underpinning the development and delivery of a blended learning program of professional development for out-of-field teachers of secondary school mathematics in Ireland. Three theoretical frameworks inform our analysis of the blended learning design. The first identifies critical dimensions of blended learning environments as a boundary …

Go to article

Aspects Of Quantum Theory In General Relativity And Cosmology, Eamon Mccaughey Jan 2020

Aspects Of Quantum Theory In General Relativity And Cosmology, Eamon Mccaughey

Doctoral

After a brief introduction to Cosmology some quantum aspects of General Relativity and cosmology are presented. The radial motion of a massive particles in the ergosphere of the Kerr Black Hole is considered. Screening of Hawking radiation and shielding of the Penrose process is examined in the context of the region of negative energy inside the ergosphere. Tunnelling of such particles between the boundaries of the classically forbidden region will be considered and the transmission coefficient determined. The evolution of Primordial black holes in standard and Loop Quantum Cosmology is reviewed. A stability analysis of Einstein’s universe in both classical …

Go to article

Modelling Interactions Among Offenders: A Latent Space Approach For Interdependent Ego-Networks, Isabella Gollini, Alberto Caimo, Paolo Campana Jan 2020

Modelling Interactions Among Offenders: A Latent Space Approach For Interdependent Ego-Networks, Isabella Gollini, Alberto Caimo, Paolo Campana

Articles

Illegal markets are notoriously difficult to study. Police data offer an increasingly exploited source of evidence. However, their secondary nature poses challenges for researchers. A key issue is that researchers often have to deal with two sets of actors: targeted and non-targeted. This work develops a latent space model for interdependent ego-networks purposely created to deal with the targeted nature of police evidence. By treating targeted offenders as egos and their contacts as alters, the model (a) leverages on the full information available and (b) mirrors the specificity of the data collection strategy. The paper then applies this approach to …

Go to article

On The Intermediate Long Wave Propagation For Internal Waves In The Presence Of Currents, Joseph Cullen, Rossen Ivanov Jan 2020

On The Intermediate Long Wave Propagation For Internal Waves In The Presence Of Currents, Joseph Cullen, Rossen Ivanov

Articles

A model for the wave motion of an internal wave in the presence of current in the case of intermediate long wave approximation is studied. The lower layer is considerably deeper, with a higher density than the upper layer. The flat surface approximation is assumed. The fluids are incompressible and inviscid. The model equations are obtained from the Hamiltonian formulation of the dynamics in the presence of a depth-varying current. It is shown that an appropriate scaling leads to the integrable Intermediate Long Wave Equation (ILWE). Two limits of the ILWE leading to the integrable Benjamin-Ono and KdV equations are …

Go to article

Camassa-Holm Cuspons, Solitons And Their Interactions Via The Dressing Method, Rossen Ivanov, Tony Lyons, Nigel Orr Jan 2020

Camassa-Holm Cuspons, Solitons And Their Interactions Via The Dressing Method, Rossen Ivanov, Tony Lyons, Nigel Orr

Articles

A dressing method is applied to a matrix Lax pair for the Camassa–Holm equation, thereby allowing for the construction of several global solutions of the system. In particular, solutions of system of soliton and cuspon type are constructed explicitly. The interactions between soliton and cuspon solutions of the system are investigated. The geometric aspects of the Camassa–Holm equation are re-examined in terms of quantities which can be explicitly constructed via the inverse scattering method.

Go to article

Integrable Negative Flows Of The Heisenberg Ferromagnet Equation Hierarchy, Rossen Ivanov Jan 2020

Integrable Negative Flows Of The Heisenberg Ferromagnet Equation Hierarchy, Rossen Ivanov

Articles

We study the negative flows of the hierarchy of the integrable Heisenberg ferromagnet model and their soliton solutions. The first negative flow is related to the so-called short pulse equation. We provide a framework which generates Lax pairs for the other members of the hierarchy. The application of the dressing method is illustrated with the derivation of the one-soliton solution.

Go to article

Stability Analysis Of Einstein's Universe In Loop Quantum Cosmology, Eamon Mccaughey Jan 2020

Stability Analysis Of Einstein's Universe In Loop Quantum Cosmology, Eamon Mccaughey

Articles

A stability analysis of Einstein’s universe in both classical General Relativity and semiclassical Loop Quantum Cosmology regimes is presented. The stability properties of the General Relativity model are significantly altered due to Loop Quantum Gravity corrections. Comparisons between both dynamical systems are considered on the basis of these modifications. The Loop Quantum Cosmology solutions are restricted to an open universe model (k = -1) and represent a cyclic universe. The integrals of motion for both systems are found and their Hamiltonian structure determined.

Go to article

Formation Of P-N Junctions In Nanoparticle Cerium Oxide Electrolytic Cells Displaying Memristive Switching Behaviour, Rafaela Cristina De Carvalho, Tony Betts, John Cassidy Jan 2020

Formation Of P-N Junctions In Nanoparticle Cerium Oxide Electrolytic Cells Displaying Memristive Switching Behaviour, Rafaela Cristina De Carvalho, Tony Betts, John Cassidy

Articles

A macro-scale metal–semiconductor–metal device comprising CeO2 nanoparticles cast from a suspension of cerium dioxide formed by a novel synthetic method was fabricated. Thin CeO2 films of 40 nm thickness placed between panels of aluminium and/or copper displayed memristive-like resistive switching behaviour upon the application of potential sweeps ranging between −0.6 V and 0.6 V. A mechanism is proposed based on the notion that an electrolytic cell operates under such conditions with the initial formation of p and n-type regions within the central semiconductive thin film. Evidence is presented for the existence of numerous point defects in these nanosized …

Go to article

First Prev Next Last