Frontier Applications Research Articles

Surface study of irradiated sapphires from Phrae Province, Thailand using AFM

The irradiation is one of the gemstone enhancements for improving the gem quality. Typically, there are many varieties of irradiated gemstones in the gem market such as diamond, topaz, and sapphire. However, it is hard to identify the gemstones before and after irradiation. The aim of this study is to analyze the surface morphology for classifying the pristine and irradiated sapphires using atomic force microscope (AFM). In this study, the sapphire samples were collected from Phrae Province, Thailand. The samples were irradiated by high energy electron beam for a dose of ionizing radiation at 40,000 kGy. As the results, the surface morphology of pristine sapphires shows regular atomic arrangement, whereas, the surface morphology of irradiated sapphires shows the nano-channel observed by the 2D and 3D AFM images. The atomic step height and root mean square roughness have changed after irradiation due to the micro-structural defect on the sapphire surface. Therefore, this study is a frontier application for sapphire identification before and after irradiation.

Solvent-Free Synthesis of Uniform MOF Shell-Derived Carbon Confined SnO2 /Co Nanocubes for Highly Reversible Lithium Storage.

Tin dioxide (SnO2 ) has attracted much attention in lithium-ion batteries (LIBs) due to its abundant source, low cost, and high theoretical capacity. However, the large volume variation, irreversible conversion reaction limit its further practical application in next-generation LIBs. Here, a novel solvent-free approach to construct uniform metal-organic framework (MOF) shell-derived carbon confined SnO2 /Co (SnO2 /Co@C) nanocubes via a two-step heat treatment is developed. In particular, MOF-coated CoSnO3 hollow nanocubes are for the first time synthesized as the intermediate product by an extremely simple thermal solid-phase reaction, which is further developed as a general strategy to successfully obtain other uniform MOF-coated metal oxides. The as-synthesized SnO2 /Co@C nanocubes, when tested as LIB anodes, exhibit a highly reversible discharge capacity of 800 mAh g-1 after 100 cycles at 200 mA g-1 and excellent cycling stability with a retained capacity of 400 mAh g-1 after 1800 cycles at 5 A g-1 . The experimental analyses demonstrate that these excellent performances are mainly ascribed to the delicate structure and a synergistic effect between Co and SnO2 . This facile synthetic approach will greatly contribute to the development of functional metal oxide-based and MOF-assisted nanostructures in many frontier applications.

Myocardial T2* Mapping with Ultrahigh Field Magnetic Resonance: Physics and Frontier Applications

Cardiovascular magnetic resonance imaging (CMR) has become an indispensable clinical tool for the assessment of morphology, function and structure of the heart muscle. By exploiting quantification of the effective transverse relaxation time (T2*) CMR also affords myocardial tissue characterization and probing of cardiac physiology, both being in the focus of ongoing research. These developments are fueled by the move to ultrahigh magnetic field strengths, which permits enhanced sensitivity and spatial resolution that help to overcome limitations of current clinical MR systems with the goal to contribute to a better understanding of myocardial (patho)physiology in vivo. In this context, the aim of this report is to introduce myocardial T2* mapping at ultrahigh magnetic fields as a promising technique to non-invasively assess myocardial (patho)physiology. For this purpose the basic principles of T2* assessment, the biophysical mechanisms determining T2* and (pre)clinical applications of myocardial T2* mapping are presented. Technological challenges and solutions for T2* sensitized CMR at ultrahigh magnetic field strengths are discussed followed by a review of acquisition techniques and post processing approaches. Preliminary results derived from myocardial T2* mapping in healthy subjects and cardiac patients at 7.0 Tesla are presented. A concluding section discusses remaining questions and challenges and provides an outlook on future developments and potential clinical applications.

Nanocellulose as a sustainable biomass material: structure, properties, present status and future prospects in biomedical applications.

Nanocellulose, extracted from the most abundant biomass material cellulose, has proved to be an environmentally friendly material with excellent mechanical performance owing to its unique nano-scaled structure, and has been used in a variety of applications as engineering and functional materials. The great biocompatibility and biodegradability, in particular, render nanocellulose promising in biomedical applications. In this review, the structure, treatment technology and properties of three different nanocellulose categories, i.e., nanofibrillated cellulose (NFC), nanocrystalline cellulose (NCC) and bacterial nanocellulose (BNC), are introduced and compared. The cytotoxicity, biocompatibility and frontier applications in biomedicine of the three nanocellulose categories were the focus and are detailed in each section. Future prospects concerning the cytotoxicity, applications and industrial production of nanocellulose are also discussed in the last section.

Influence of linear chirp on the output characteristics of cross polarized wave with saturated power density

Ultra-short and ultra-intense laser is one of the hottest research spot of laser technology and strong field physics, due to its challenging and the frontier application research. As the key specification of ultrafast ultrahigh intensity laser pulse, the contrast ratio is very influential on the effect of laser-matter interaction. To perform the laser-matter interaction experiments at a high power level, the contrast is required to be as high as 1010 to prevent preplasma dynamics. To solve these problems, one has proposed many methods to improve the contrast of ultrafast laser, such as using the saturable absorbers, double chirped pulse amplification, plasma mirrors and the cross-polarized wave (XPW) generation. The XPW technology can not only enhance the contrast of the pulse by 3-4 orders of magnitude without introducing any space dispersion, but also extend the output spectrum to support shorter pulse duration. The XPW is a nonlinear filter technique in third-order nonlinear crystal with anisotropic susceptibility. Because of its simple and all-solid-state structure, the XPW technique has become one of the most effective methods to enhance the temporal pulse contrast and deliver shorter pulse duration in the field of high peak-power ultrafast lasers. This method has been used in many large laser facilities under construction or upgrades, such as the Apollon and ELI, the contrast ratio as high as 1010 has been achieved. It is known that the conversion efficiency and spectral characteristics of XPW have a strong dependence on the spatial and temporal magnitudes of the input driving pulse. In our experiment, it is found that the various changes of the driven pulse properties have different influences on the characteristics of XPW pulses. The relationship between the linear dispersion of driven pulse and temporal property of XPW is investigated theoretically. In addition, an experiment on verifying the theory is conducted by taking advantage of a programmable acousto-optic dispersion filter. The experimental results fit well to the theoretical results while some new phenomena emerge when the intensity in the BaF2 crystal reaches a saturation threshold. The spectral broadening capability of XPW becomes stronger and exceeds a theoretical upper limit. The pulse width can also be compressed to shorter than the theoretical limit. It is found that there are significant differences in spectral shape and conversion efficiency between the XPW signals by applying the opposite linear chirps to the driving pulse. A further analysis and theoretical explanation of these new phenomena are also presented.

In Situ Atomic/Molecular Layer-by-Layer Deposition of Inorganic–Organic Coordination Network Thin Films from Gaseous Precursors

Crystalline inorganic–organic coordination network materials possess a property palette highly attractive for a number of frontier applications. In many prospective applications of these materials, high-quality thin films would be required. Gas-phase thin-film techniques could potentially provide a number of advantages over the current liquid-phase techniques for depositing such state-of-the-art hybrid thin films. The strongly emerging atomic/molecular layer deposition (ALD/MLD) technique in particular enables the rational fabrication of inorganic–organic thin films in a digital atomic/molecular layer-by-layer manner through successive gas-to-surface reactions of inorganic and organic precursors, but the resultant films have been amorphous. Here, we demonstrate the in situ ALD/MLD growth of well-crystalline calcium terephthalate (Ca-TP) coordination network thin films in a wide deposition temperature range. We moreover investigate the water absorption/desorption characteristics of the films and report att...

ChemInform Abstract: Graphene Oxide: Strategies for Synthesis, Reduction and Frontier Applications

AbstractReview: 263 refs.

Meningioma Genomics: Diagnostic, Prognostic, and Therapeutic Applications.

There has been a recent revolution in our understanding of the genetic factors that drive meningioma, punctuating an equilibrium that has existed since Cushing’s germinal studies nearly a century ago. A growing appreciation that meningiomas share similar biologic features with other malignancies has allowed extrapolation of management strategies and lessons from intra-axial central nervous system neoplasms and systemic cancers to meningiomas. These features include a natural proclivity for invasion, frequent intratumoral heterogeneity, and correlation between biologic profile and clinical behavior. Next-generation sequencing has characterized recurrent somatic mutations in NF2, TRAF7, KLF4, AKT1, SMO, and PIK3CA, which are collectively present in ~80% of sporadic meningiomas. Genomic features of meningioma further associate with tumor location, histologic subtype, and possibly clinical behavior. Such genomic decryption, along with advances in targeted pharmacotherapy, provides a maturing integrated view of meningiomas. We review recent advances in meningioma genomics and probe their potential applications in diagnostic, therapeutic, and prognostic frontiers.

STOCHASTIC PRODUCTION FRONTIER FOR THE LITHUANIAN FAMILY FARMS

The research follows neo-classical methodology to analyse the trends of the agricultural efficiency. The paper fits the stochastic production frontier to the micro data describing the performance of the Lithuanian family farms during 2004–2009 in order to define the current trends of efficiency and productivity in the sector. Indeed, this is the first application of stochastic frontiers to gauge the performance of Lithuanian family farms. The technical efficiency of the Lithuanian family farms fluctuated around 80%. The analysis confirmed that the livestock farms were peculiar with higher mean technical efficiency if compared to that of mixed or crop farms. The estimated partial output elasticities imply that the intermediate consumption was the most productive factor, whereas assets were four to six times less productive depending on the farming type. The land factor was peculiar with the lowest partial output elasticities. The research contributes to the wider discussion on the patterns of efficiency and productivity in a transition European Union Member States following the accession.

STOCHASTIC PRODUCTION FRONTIER FOR THE LITHUANIAN FAMILY FARMS

The research follows neo-classical methodology to analyse the trends of the agricultural efficiency. The paper fits the stochastic production frontier to the micro data describing the performance of the Lithuanian family farms during 2004–2009 in order to define the current trends of efficiency and productivity in the sector. Indeed, this is the first application of stochastic frontiers to gauge the performance of Lithuanian family farms. The technical efficiency of the Lithuanian family farms fluctuated around 80%. The analysis confirmed that the livestock farms were peculiar with higher mean technical efficiency if compared to that of mixed or crop farms. The estimated partial output elasticities imply that the intermediate consumption was the most productive factor, whereas assets were four to six times less productive depending on the farming type. The land factor was peculiar with the lowest partial output elasticities. The research contributes to the wider discussion on the patterns of efficiency and productivity in a transition European Union Member States following the accession.

Transparent ferrimagnetic semiconducting CuCr2O4 thin films by atomic layer deposition

We report the magnetic and optical properties of CuCr2O4 thin films fabricated by atomic layer deposition (ALD) from Cu(thd)2, Cr(acac)3, and ozone; we deposit 200 nm thick films and anneal them at 700 °C in oxygen atmosphere to crystallize the spinel phase. A ferrimagnetic transition at 140 K and a direct bandgap of 1.36 eV are determined for the films from magnetic and UV-vis spectrophotometric measurements. Electrical transport measurements confirm the p-type semiconducting behavior of the films. As the ALD technique allows the deposition of conformal pin-hole-free coatings on complex 3D surfaces, our CuCr2O4 films are interesting material candidates for various frontier applications.

Graphene oxide: strategies for synthesis, reduction and frontier applications

In this review article, we describe a general introduction to GO, its synthesis, reduction and some selected frontier applications. Its low cost and potential for mass production make GO a promising building block for functional hybrid materials.

Frontiers of the food–energy–water trilemma: Sri Lanka as a microcosm of tradeoffs

Food, energy, and water are three critical resources for humanity. As climate variability, population growth, and lifestyle changes amplify the stress placed on each of the resources, the interrelationships among food, energy, and water systems become more pronounced. Political conflict, social and cultural norms, and spatial and temporal distribution of the resources add additional layers of complexity. It is in this context that the significance of understanding the impacts of water scarcity on the decisions around food and energy productions has emerged. Our work establishes tradeoff frontiers (TFs) as a method useful in illustrating the system-level tradeoffs between allocating water for food and water for energy. This paper illustrates how TFs can be used to (1) show how scarcity in water resources affects the tradeoffs between food and energy and (2) explore the political and social constraints that can move production away from what is feasible technically. We use Sri Lanka, a country where water resources are variable both in space and time and a country with relatively self-contained energy and agricultural sectors, as a microcosm of the food security, energy security, and water security trilemma. Nevertheless, our application of tradeoff frontiers is applicable widely to other systems.

Defining Better Test Strategies with Tradespace Exploration Techniques and Pareto Fronts: Application in an Industrial Project

Test strategies are usually defined following a point-design like method. Starting with a set of verification requirements and programmatic constraints, and usually with a generic test sequence, a baseline test approach is defined. Then, the baseline is optimized until an acceptable strategy is found. Academia has consistently shown however the benefits of using tradespace exploration techniques instead of point-based designs. Some industrial applications seem to corroborate such findings. Yet, both academia and industry have limited the use of tradespace exploration techniques to selecting design concepts. This paper proposes that broadening the use of tradespace exploration techniques and Pareto frontiers to other activities in the field of systems engineering domain yields similar benefits. In particular, this paper presents the actual application of tradespace exploration techniques and Pareto frontiers in an industrial context to select a test strategy for a system. This paper provides thus three main contributions. First, the paper demonstrates that tradespace exploration and Pareto frontiers can be beneficial beyond concept selection. Second, the paper presents a process to use tradespace exploration techniques and Pareto frontiers for selecting test strategies. Finally, the paper showcases the application of the proposed technique and process in a real industrial setup, which yielded a number of lessons learnt.

CEO compensation and bank efficiency: An application of conditional nonparametric frontiers

The paper investigates in a dynamic context the effect of Chief Executive Officer (CEO) bonus and salary payments on banks’ technical efficiency levels. Our methodological framework incorporates the latest developments on the probabilistic approach of efficiency measurement as introduced by Bădin et al. (2012). We apply time-dependent conditional efficiency estimates to analyse a sample of 37 US banks for the period from 2003 to 2012. The empirical evidence reveals a non-linear relationship between CEO bonus and salary payments and banks’ efficiency levels. More specifically it is reported that salary and bonus payments affect differently banks’ technological change and technological catch-up levels. Finally, the empirical evidence suggests that higher salary and bonus payments are not always aligned with higher technical efficiency levels.

W(h)ither human cardiac and body magnetic resonance at ultrahigh fields? technical advances, practical considerations, applications, and clinical opportunities

The objective of this study was to document and review advances and groundbreaking progress in cardiac and body MR at ultrahigh fields (UHF, B0 ≥ 7.0 T) with the goal to attract talent, clinical adopters, collaborations and resources to the biomedical and diagnostic imaging communities. This review surveys traits, advantages and challenges of cardiac and body MR at 7.0 T. The considerations run the gamut from technical advances to clinical opportunities. Key concepts, emerging technologies, practical considerations, frontier applications and future directions of UHF body and cardiac MR are provided. Examples of UHF cardiac and body imaging strategies are demonstrated. Their added value over the kindred counterparts at lower fields is explored along with an outline of research promises. The achievements of cardiac and body UHF-MR are powerful motivators and enablers, since extra speed, signal and imaging capabilities may be invested to overcome the fundamental constraints that continue to hamper traditional cardiac and body MR applications. If practical obstacles, concomitant physics effects and technical impediments can be overcome in equal measure, sophisticated cardiac and body UHF-MR will help to open the door to new MRI and MRS approaches for basic research and clinical science, with the lessons learned at 7.0 T being transferred into broad clinical use including diagnostics and therapy guiding at lower fields. Copyright © 2015 John Wiley & Sons, Ltd.

Frontier Analysis

This article presents a comprehensive review of frontier studies in the tourism literature. We discuss the main advantages and disadvantages of the various frontier approaches, in particular, the nonparametric and parametric frontier approaches. The study further differentiates between micro and macro applications of these approaches, summarizing and critically reviewing the characteristics of the existing studies. We also conduct a meta-analysis to create an overview of the efficiency results of frontier applications. This allows for an investigation of the impact of frontier methodology on tourism research. The present review also highlights the limitations of existing studies and suggests an agenda for future research.

Ophthalmological imaging with ultrahigh field magnetic resonance tomography: technical innovations and frontier applications

This review documents technical progress in ophthalmic magnetic resonance imaging (MRI) at ultrahigh fields (UHF, B(0) ≥ 7.0 T). The review surveys frontier applications of UHF-MRI tailored for high spatial resolution in vivo imaging of the eye, orbit and optic nerve. Early examples of clinical ophthalmic UHF-MRI including the assessment of melanoma of the choroid membrane and the characterisation of intraocular masses are demonstrated. A concluding section ventures a glance beyond the horizon and explores research promises along with future directions of ophthalmic UHF-MRI.

Editorial — Leonid Pavlovich Shilnikov

This special issue presents a selection of papers from the conference “Dynamics, Bifurcations and Strange Attractors” dedicated to the memory of Leonid Pavlovich Shilnikov (1934–2011) to commemorate his contributions to the theory of dynamical systems and bifurcations. The conference was held at the Lobachevsky State University of Nizhny Novgorod, Russia, on 1–5 July 2013. The conference was attended by 155 participants from all over the world, who contributed to the three focal topics: bifurcations and strange attractors; dynamical systems with additional structures (Hamiltonian, time-reversible, etc.); applications of dynamical systems. The topics were chosen in confluence with pivotal contributions by L. P. Shilnikov to the fields. The speakers presented their current research and outlined future directions in both theory and frontier applications. The organizers of the conference are grateful to its sponsors: Russian Foundation of Basic Research, D. Zimin’s Russian Charitable Foundation “Dynasty,” R&D company Mera-NN, and K. V. Kirsenko (Russia), as well as Office of Naval Research (USA) and its officers, Drs. M. Harper (UK) and M. Shlesinger (USA). We thank the Editors-in-Chief of the International Journal of Bifurcations and Chaos: Ron Chen and Leon Chua for having the proceedings published here. L. P. Shilnikov served on the Editorial Board of the journal from the time it was founded. Our dear friend, mentor and fellow researcher, L. P. Shilnikov conceptualized the theory of global bifurcations of high-dimensional systems and was one of the founders of the mathematical theory of dynamical chaos. He built a profound research school in the city of Nizhny Novgorod (Gorky formerly) — the Shilnikov School that continues to this day. His works greatly influenced the overall development of the mathematical theory of dynamical systems as well as nonlinear dynamics, in general. Shilnikov’s findings have been included in most textand reference books, and are used worldwide by mathematics students and nonlinear dynamists to study the qualitative theory of dynamical systems and chaos. The elegance and completeness of his results let them reach “the heart of the matter,” and provide applied researchers with an in-depth mathematical understanding of the outcomes of natural experiments. The popularity and appreciation are due to the “living classic” status attained by Professor Shilnikov over several decades of his life through continuous hard work on bifurcation theory of multidimensional dynamical systems, mathematical chaos theory and theory of strange attractors. L. P. Shilnikov was born in Kotelnich, Kirov region of Russia on December 17, 1934. After graduating from a local high school in 1952, he became a student in the Department of Physics and Mathematics at Gorky State University. After graduation in 1957, he continued his PhD studies at the same university. He defended his PhD thesis “On birth of stable periodic orbits from singular trajectories” in 1962, it focused on the multidimensional generalization of basic homoclinic bifurcations, which were originally discovered and studied for systems on a plane by A. A. Andronov and E. A. Leontovich in the early 1930s.

Is corruption grease, grit or a gamble? Corruption increases variance of productivity across countries

The effect of corruption on economic growth has attracted interest in empirical development economics. The conventional view of corruption as impediment for growth has been challenged by the ‘grease-on-the-wheels’ hypothesis. We take a new perspective on the issue and suggest corruption as macro risk, referred to as a ‘gamble’ hypothesis. Using cross-country data and two alternative indicators of corruption, we find corruption to be a significant driver of heteroscedasticity in total productivity. This supports the new gamble hypothesis. We also note some misleading interpretations in the previously published frontier applications. To avoid these shortcomings, we apply a flexible semi-nonparametric estimator.