bluuebunny/crossref_metadata_2025 huggingface dataset:
Simultaneous Measurements of Chemical Compositions of Fine Particles during Winter Haze Period in Urban Sites in China and Korea
Authors: Park Minhan , Wang Yujue , Chong Jihyo , Lee Haebum , Jang Jiho , Song Hangyul , Kwak Nohhyeon , Borlaza Lucille Joanna S. , Maeng Hyunok , Cosep Enrique Mikhael R. , Denna Ma. Cristine Faye J. , Chen Shiyi , Seo Ilhwa , Bae Min-Suk , Jang Kyoung-Soon , Choi Mira , Kim Young Hwan , Park Moonhee , Ryu Jong-Sik , Park Sanghee , Hu Min , Park Kihong
Published: March 2020

We performed simultaneous measurements of chemical compositions of fine particles in Beijing, China and Gwangju, Korea to better understand their sources during winter haze period. We identified PM2.5 events in Beijing, possibly caused by a combination of multiple primary combustion sources (biomass burning, coal burning, and vehicle emissions) and secondary aerosol formation under stagnant conditions and/or dust sources under high wind speeds. During the PM2.5 events in Gwangju, the contribution of biomass burning and secondary formation of nitrate and organics to the fine particles content significantly increased under stagnant conditions. We commonly observed the increases of nitrogen-containing organic compounds and biomass burning inorganic (K+) and organic (levoglucosan) markers, suggesting the importance of biomass burning sources during the winter haze events (except dust event cases) at both sites. Pb isotope ratios indicated that the fraction of Pb originated from possibly industry and coal combustion sources increased during the PM2.5 events in Gwangju, relative to nonevent days.
North Atlantic Hurricane Winds in Warmer than Normal Seas
Authors: Trepanier Jill C.
Published: March 2020

Tropical cyclones devastate coastlines around the world. The United States and surrounding areas experienced catastrophic extreme events in recent hurricane seasons. Understanding extreme hurricanes and how they change in a warming ocean environment is of the utmost importance. This study makes use of the historical, positive relationship between average summer sea surface temperatures (SSTs) and maximum hurricane wind speeds across the North Atlantic Basin from 1854–2018. Geographically weighted regression shows how the relationship between hurricane winds and SSTs varies across space. Each localized slope is used to increase historical wind speeds to represent winds in a three-degree Celsius warmer-than-average sea surface. The winds are then used to estimate the maximum intensity of the thirty-year hurricane (one with a 3.3% annual probability of occurrence) across the hexagonal grid using extreme value statistics. Viewing the results spatially allows for geographic patterns to emerge in the overall risk of major hurricane occurrence in warm SST environments. This study showcases the difference in the historical extreme compared to the potential future extreme in the hopes to better inform those charged with making important, life-saving decisions along the U.S. and neighboring coasts.
Systolic Aspects of Black Hole Entropy
Authors: Kalogeropoulos Nikolaos
Published: March 2020

We attempt to provide a mesoscopic treatment of the origin of black hole entropy in (3 + 1)-dimensional spacetimes. We ascribe this entropy to the non-trivial topology of the space-like sections Σ of the horizon. This is not forbidden by topological censorship, since all the known energy inequalities needed to prove the spherical topology of Σ are violated in quantum theory. We choose the systoles of Σ to encode its complexity, which gives rise to the black hole entropy. We present hand-waving reasons why the entropy of the black hole can be considered as a function of the volume entropy of Σ . We focus on the limiting case of Σ having a large genus.
Acquisition of Ownership Illusion with Self-Disownership in Neurological Patients
Authors: Pazzaglia Mariella , Giannini Anna Maria , Federico Francesca
Published: March 2020

The multisensory regions in frontoparietal cortices play a crucial role in the sense of body and self. Disrupting this sense may lead to a feeling of disembodiment, or more generally, a sense of disownership. Experimentally, this altered consciousness disappears during illusory own-body perceptions, increasing the intensity of perceived ownership for an external virtual limb. In many clinical conditions, particularly in individuals with a discontinuous or absent sense of bodily awareness, the brain may effortlessly create a convincing feeling of body ownership over a surrogate body or body part. The immediate visual input dominates the current bodily state and induces rapid plastic adaptation that reconfigures the dynamics of bodily representation, allowing the brain to acquire an alternative sense of body and self. Investigating strategies to deconstruct the lack of a normal sense of bodily ownership, especially after a neurological injury, may aid the selection of appropriate clinical treatment.
Experimental Investigation of Adhesion Failure between Waterproof Coatings and Terrace Tiles under Usage Loads
Authors: Francke Barbara , Piekarczuk Artur
Published: March 2020

This paper analyses the mechanism of the loss of functional properties of water-impermeable products used under ceramic tiles bonded with adhesives. Recorded damages were caused by selected ageing factors and were measured by the loss of adhesion of individual layers of the set. The analyzed phenomenon is found mainly on terraces and balconies located in a mid-European transitional climate, i.e., exposed to temperatures passing through 0 °C for three seasons a year. The tests reflected the action of three main functional factors, i.e., temperatures, water and freeze/thaw cycles. Tested waterproof coatings were grouped into three types, i.e., dispersion, cementitious and reaction resin-based products. Research kits consisted of liquid-applied water-impermeable products laid on a concrete substrate, adhesives and tiles. Comparing the effects of the action of the above-mentioned ageing factors revealed that water has the greatest impact on the reduction of the tensile adhesion strength of such sets. The adhesion of waterproof coatings to the concrete substrate showed higher values than the adhesion between the waterproof coating and the tile adhesive layers, regardless of the coating material. Both for samples not exposed to ageing factors, and for those exposed to such impacts, failure usually occurred in the adhesive layer or between the tile adhesive and the waterproof coating, without damaging the waterproof layer. The loss of adhesion of finishing layers to the substrate was not accompanied by a loss of tightness of the waterproof coating. The impact of negative water ageing was particularly destructive on the adhesion of cement-based tile adhesives to waterproof coatings made of polymer with a water dispersion of absorbability above 7% (V/V). There was no correlation among the results of adhesion of the finishing layers to the waterproofing layer after the action of the three ageing factors, i.e., water contact, elevated temperature and freeze/thaw cycles.
Exploiting Direct Current Plasma Electrolytic Oxidation to Boost Photoelectrocatalysis
Authors: Franz Silvia , Arab Hamed , Lucotti Andrea , Castiglioni Chiara , Vicenzo Antonello , Morini Federico , Bestetti Massimiliano
Published: March 2020

In this study, we report an investigation of the photoelectrochemical activity of TiO2 films formed by DC plasma electrolytic oxidation (PEO) at a variable potential in a sulfuric acid electrolyte at 0 and 25 °C. The surface morphology was mainly determined by the oxide-forming potential. X-Ray Diffraction and Raman analyses showed that the relative amount of the anatase and rutile phases varied from 100% anatase at low potential (110–130 V) to 100% rutile at high potential (180–200 V), while mixed-phase oxide films formed at intermediate potential. Correspondingly, the band gap of the TiO2 films decreased from about 3.20 eV (pure anatase) to 2.94 eV (pure rutile) and was red-shifted about 0.1 eV by reducing the electrolyte temperature from 25 °C to 0 °C. Glow-Discharge Optical Emission Spectroscopy (GD-OES) and X-ray Photoelectron Spectroscopy (XPS) analyses evidenced S-containing species located preferentially close to the TiO2/Ti interface. The photoelectrochemical activity was assessed by measuring the incident photon-to-current efficiency (IPCE) under Ultraviolet C (UV-C) irradiation, which showed a non-gaussian normal trend as a function of the PEO cell potential, with maximum values exceeding 80%. Photoelectrocatalytic activity was assessed by decolorization of model solutions containing methylene blue. Photoanodes having higher IPCE values showed faster decolorization kinetics.
Study on Thermal Decomposition Behavior, Gaseous Products, and Kinetic Analysis of Bis-(Dimethylglyoximato) Nickel(II) Complex Using TG-DSC-FTIR-MS Technique
Authors: Yao Ergang , Xu Siyu , Zhao Fengqi , Huang Taizhong , Li Haijian , Zhao Ningning , Yi Jianhua , Yang Yanjing , Wang Changjian
Published: March 2020

The fiber-like bis-(dimethylglyoximato) nickel(II) complex, Ni(DMG)2 was successfully synthesized. The obtained samples were characterized by SEM-EDS, FT-IR, XRD, and XPS. The TG-DSC-FTIR-MS coupling technique was used to characterize the thermal decomposition behavior and evolved gas analysis of Ni(DMG)2. The non-isothermal decomposition reaction kinetic parameters were obtained by both combined kinetic analysis and isoconversional Vyazovkin methods. It was found that Ni(DMG)2 begins to decompose at around 280 °C, and a sharp exothermic peak is observed in the DSC curve at about 308.2 °C at a heating rate of 10 °C·min−1. The main gaseous products are H2O, NH3, N2O, CO, and HCN, and the content of H2O is significantly higher than that of the others. The activation energy obtained by the combined kinetic analysis method is 170.61 ± 0.65 kJ·mol−1. The decomposition process can be described by the random nucleation and growth of the nuclei model. However, it was challenging to attempt to evaluate the reaction mechanism precisely by one ideal kinetic model.
Gold-Based Nanoparticles on Amino-Functionalized Mesoporous Silica Supports as Nanozymes for Glucose Oxidation
Authors: Ortega-Liebana M. Carmen , Bonet-Aleta Javier , Hueso Jose L. , Santamaria Jesus
Published: March 2020

The transformation of glucose represents a topic of great interest at different levels. In the first place, glucose is currently conceived as a green feedstock for the sustainable production of chemicals. Secondly, the depletion of glucose at the cellular level is currently envisioned as a promising strategy to treat and alter the erratic metabolism of tumoral cells. The use of natural enzymes offers multiple advantages in terms of specificity towards the glucose substrate but may lack sufficient robustness and recyclability beyond the optimal operating conditions of these natural systems. In the present work, we have evaluated the potential use of an inorganic based nanohybrid containing gold nanoparticles supported onto ordered mesoporous supports. We have performed different assays that corroborate the enzyme-mimicking response of these inorganic surrogates towards the selective conversion of glucose into gluconic acid and hydrogen peroxide. Moreover, we conclude that these enzyme-like mimicking surrogates can operate at different pH ranges and under mild reaction conditions, can be recycled multiple times and maintain excellent catalytic response in comparison with other gold-based catalysts.
Photocatalytic Reforming for Hydrogen Evolution: A Review
Authors: Yao Yuan , Gao Xinyu , Li Zizhen , Meng Xiangchao
Published: March 2020

Hydrogen is considered to be an ideal energy carrier to achieve low-carbon economy and sustainable energy supply. Production of hydrogen by catalytic reforming of organic compounds is one of the most important commercial processes. With the rapid development of photocatalysis in recent years, the applications of photocatalysis have been extended to the area of reforming hydrogen evolution. This research area has attracted extensive attention and exhibited potential for wide application in practice. Photocatalytic reforming for hydrogen evolution is a sustainable process to convert the solar energy stored in hydrogen into chemical energy. This review comprehensively summarized the reported works in relevant areas, categorized by the reforming precursor (organic compound) such as methanol, ethanol and biomass. Mechanisms and characteristics for each category were deeply discussed. In addition, recommendations for future work were suggested.
Polymer Nanoparticle Identification and Concentration Measurement Using Fiber-Enhanced Raman Spectroscopy
Authors: Pollard Mark R. , Sparnacci Katia , Wacker Lars J. , Kerdoncuff Hugo
Published: March 2020

We present a measurement technique for chemical identification and concentration measurement of polymer nanoparticles in aqueous solution, which is achieved using Raman spectroscopy. This work delivers an improvement in measurement sensitivity of 40 times over conventional Raman measurements in cuvettes by loading polymer nanoparticles into the hollow core of a microstructured optical fiber. We apply this “fiber-enhanced” system to measure the concentration of two separate samples of polystyrene particles (diameters of 60 nm and 120 nm respectively) with concentrations in the range from 0.07 to 0.5 mg/mL. The nanoliter volume formed by the fiber presents unique experimental conditions where nanoparticles are confined within the fiber core and prevented from diffusing outside the incident electromagnetic field, thereby enhancing their interaction. Our results suggest an upper limit on the size of particle that can be measured using the hollow-core photonic crystal fiber, as the increasing angular distribution of scattered light with particle size exceeds the acceptance angle of the liquid-filled fiber. We investigate parameters such as the fiber filling rate and optical properties of the filled fiber, with the aim to deliver repeatable and quantifiable measurements. This study thereby aids the on-going process to create compact systems that can be integrated into nanoparticle production settings for in-line measurements.
Ecological Niche Models Reveal Climate Change Effect on Biogeographical Regions: The Iberian Peninsula as a Case Study
Authors: Sousa-Guedes Diana , Arenas-Castro Salvador , Sillero Neftalí
Published: March 2020

How species are distributed on Earth depends largely on climate factors. Whenever these environmental conditions change, species tend to shift their distributions to reach more favourable conditions. Distinct sets of species similarly distributed (i.e., chorotypes) occur in biogeographical regions with homogeneous environmental conditions. Here, we analysed whether biogeographical regions are unstable over time (from the past to the future). We modelled the realised niche of amphibians and reptiles in the Iberian Peninsula in the present, and several past and future climate scenarios. Then, we used Jaccard’s index and the unweighted pair group method (UPGMA) to define the biogeographical regions. Our results suggest that the biogeographical regions of Iberian amphibians and reptiles changed greatly over time, due to the climatic changes between periods. Biogeographical regions composed of species with Atlantic affinities changed particularly, overall gaining suitable areas in past colder periods and losing suitable areas in warmer periods. The areas of refugia for amphibians over time corresponded to the most humid regions (north-west of the peninsula), while the most important areas for reptiles occur in the south and on the Atlantic coast. The identification of biogeographical patterns considering past climate changes is essential to better apply conservation measures.
Low-Temperature Fabrication of High-Performance and Stable GZO/Ag/GZO Multilayer Structures for Transparent Electrode Applications
Authors: Akhmedov Akmedov , Abduev Aslan , Kanevsky Vladimir , Muslimov Arsen , Asvarov Abil
Published: March 2020

Presently, research and development of indium-free stable highly transparent conductive (TC) materials is of paramount importance for the blooming world of information display systems and solar energy conversion. Development of devices based on flexible organic substrates further narrows the choice of possible TC materials due to the need for lower deposition and process temperatures. In our work, the structural, electrical, and optical performances of Ga-doped ZnO/Ag/Ga-doped ZnO (GZO/Ag/GZO) multilayered structures deposited on glass substrates by direct current (DC) magnetron sputtering in a pure Ar medium without any purposeful substrate heating have been investigated. The highest figure of merit achieved was 5.15 × 10−2 Ω−1 for the symmetric GZO/Ag/GZO multilayer, featuring GZO and Ag thicknesses of 40 and 10 nm, respectively, while the average optical transmittance was over 81% in the visible range of wavelengths and the resistivity was 2.2 × 10−5 Ω·cm. Additionally, the good durability of the performances of the multilayer structures was demonstrated by their testing in the context of long-term storage (over 500 days) in standard environmental conditions.
Biomimetic Sensitive Elements for 2,4,6-Trinitrotoluene Tested on Multi-Layered Sensors
Authors: GAVRILA Ana Mihaela , IORDACHE Tanta Verona , LAZAU Carmen , ROTARIU Traian , CERNICA Ileana , STROESCU Hermine , STOICA Mihai , ORHA Corina , BANDAS Cornelia Elena , SARBU Andrei
Published: March 2020

In spite of technological progress, most of the current techniques for 2,4,6-trinitrotoluene (TNT) detection are time consuming due to laborious sensor preparation. Thereby, the aim of this work was to enlarge the knowledge for preparing sensitive elements for TNT with the aid of molecular imprinting; a known technique used to deliver biomimetic materials. The study first depicts the auto-assembly mechanism of (TNT) with functional diamino-silanes (i.e., N-(2-aminoethyl)-3-aminopropyl methyl dimethoxysilane), via “double” Meisenheimer complexes. This mechanism is being described herein for the first time and applied further to obtain molecularly imprinted polymer (MIP) films for TNT recognition. For testing the potential application of films as chemical sensor elements, typical rebinding assays of TNT in a liquid state and the rebinding of TNT in a vapor state, using multilayered sensor chips composed of quartz-chromium (Cr)-gold (Au)-titanium oxide (TiO2), were employed. Batch rebinding experiments have shown that thinner films were more efficient on retaining TNT molecules in the first five min, with a specificity of about 1.90. The quartz-Cr-Au-TiO2-MIP capacitive sensors, tested in vapor state, registered short response times (less than 25 s), low sensitivity to humidity and high specificity for TNT.
Study on Microstructure and Tribological Performance of Diamond/Cu Composite Coating via Supersonic Laser Deposition
Authors: Wu Lijuan , Zhang Gang , Li Bo , Wang Weilin , Huang Xuanjie , Chen Zhijun , Dong Gang , Zhang Qunli , Yao Jianhua
Published: March 2020

The supersonic laser deposition (SLD) of diamond/Cu composite powder is studied over a range of laser power. The deposition efficiency, coating microstructure, cohesive/adhesive bonding, phase composition, micro-hardness, and tribological property of the diamond/Cu composite coating are investigated. The results indicate that, as laser power is increased, deposition efficiency initially increases and then declines. The diamond particles distribute uniformly in the composite coating. Due to the increase of velocity ratio and total energy by laser irradiation, the cohesive/adhesive bonding of the composite coating is improved. The composite coating can preserve the phase composition of the origin powders due to the relatively low heat input during the SLD process. Slight oxidation of the Cu powder can be detected in the coatings prepared with high laser power, which has adverse effects on material deposition. The SLD-diamond/Cu composite coating has superior wear-resistance because of low friction coefficient, high micro-hardness, and uniformly distributed diamond particles.
TCAD Simulation of the Doping-Less TFET with Ge/SiGe/Si Hetero-Junction and Hetero-Gate Dielectric for the Enhancement of Device Performance
Authors: Han Tao , Liu Hongxia , Chen Shupeng , Wang Shulong , Xie Haiwu
Published: March 2020

The device structure of DLTFET is optimized by the Silvaco TCAD software to solve the problems of lower on-state current and larger miller capacitance of traditional doping-less tunneling field effect transistors (DLTFETs), and the performance can be greatly improved. Different from the traditional DLTFETs, the source region and pocket region of the doping-less TFET with the Ge/SiGe/Si hetero-junction and hetero-gate dielectric (H-DLTFET), respectively, use the narrow band-gap semiconductor Ge and SiGe materials, and the channel and drain region both use the silicon material. The H-DLTFET device use the Ge/SiGe hetero-junction engineering to decrease the tunneling barrier width, increase the band-to-band tunneling current, and obtain the higher current switching ratio and ultra-low sub-threshold swing (SS). Besides, the gate dielectric under auxiliary gate uses the low-k dielectric SiO2 material, which can effectively reduce the miller capacitance and improve the capacitance and frequency characteristics. The on-state current, switching ratio, trans-conductance, output current, and output conductance values of H-DLTFET can be increased by two, two, one, one, and one order of magnitude when compared with the DLTFET, respectively. Meanwhile, the point SS and average SS, respectively, decrease from 13 mV/Dec and 31.6 mV/Dec to 5 mV/Dec and 14.3 mV/Dec, and the gate-drain capacitance decrease from 0.99 fF/μm to 0.1 fF/μm. Besides, the cutoff frequency and gain bandwidth product of H-DLTFET are much larger than that of DLTFET, which can be explained by the excellent DC characteristics. The above simulation results show that the H-DLTFET has the better frequency characteristics, so it is more suitable for applications of ultra-low-power integrated circuits.
Dual Energy X-ray Methods for the Characterization, Quantification and Imaging of Calcification Minerals and Masses in Breast
Authors: Martini Niki , Koukou Vaia , Michail Christos , Fountos George
Published: March 2020

Dual energy (DE) technique has been used by numerous studies in order to detect breast cancer in early stages. Although mammography is the gold standard, the dual energy technique offers the advantage of the suppression of the contrast between adipose and glandular tissues and reveals pathogenesis that is not present in conventional mammography. Both dual energy subtraction and dual energy contrast enhanced techniques were used in order to study the potential of dual energy technique to assist in detection or/and visualization of calcification minerals, masses and lesions obscured by overlapping tissue. This article reviews recent developments in this field, regarding: i) simulation studies carried out for the optimizations of the dual energy technique used in order to characterize and quantify calcification minerals or/and visualize suspected findings, and ii) the subsequent experimental verifications, and finally, the adaptation of the dual energy technique in clinical practice.
From Equilibrium Liquid Crystal Formation and Kinetic Arrest to Photonic Bandgap Films Using Suspensions of Cellulose Nanocrystals
Authors: Schütz Christina , Bruckner Johanna R. , Honorato-Rios Camila , Tosheva Zornitza , Anyfantakis Manos , Lagerwall Jan P. F.
Published: March 2020

The lyotropic cholesteric liquid crystal phase developed by suspensions of cellulose nanocrystals (CNCs) has come increasingly into focus from numerous directions over the last few years. In part, this is because CNC suspensions are sustainably produced aqueous suspensions of a fully bio-derived nanomaterial with attractive properties. Equally important is the interesting and useful behavior exhibited by solid CNC films, created by drying a cholesteric-forming suspension. However, the pathway along which these films are realized, starting from a CNC suspension that may have low enough concentration to be fully isotropic, is more complex than often appreciated, leading to reproducibility problems and confusion. Addressing a broad audience of physicists, chemists, materials scientists and engineers, this Review focuses primarily on the physics and physical chemistry of CNC suspensions and the process of drying them. The ambition is to explain rather than to repeat, hence we spend more time than usual on the meanings and relevance of the key colloid and liquid crystal science concepts that must be mastered in order to understand the behavior of CNC suspensions, and we present some interesting analyses, arguments and data for the first time. We go through the development of cholesteric nuclei (tactoids) from the isotropic phase and their potential impact on the final dry films; the spontaneous CNC fractionation that takes place in the phase coexistence window; the kinetic arrest that sets in when the CNC mass fraction reaches ∼10 wt.%, preserving the cholesteric helical order until the film has dried; the ’coffee-ring effect’ active prior to kinetic arrest, often ruining the uniformity in the produced films; and the compression of the helix during the final water evaporation, giving rise to visible structural color in the films.
Mechanical and Magnetic Properties of the High-Entropy Alloys for Combinatorial Approaches
Authors: Huang E-Wen , Hung Guo-Yu , Lee Soo Yeol , Jain Jayant , Chang Kuan-Pang , Chou Jing Jhe , Yang Wen-Chi , Liaw Peter K.
Published: March 2020

This review summarizes the state of high-entropy alloys and their combinatorial approaches, mainly considering their magnetic applications. Several earlier studies on high-entropy alloy properties, such as magnetic, wear, and corrosion behavior; different forms, such as thin films, nanowires, thermal spray coatings; specific treatments, such as plasma spraying and inclusion effects; and unique applications, such as welding, are summarized. High-entropy alloy systems that were reported for both their mechanical and magnetic properties are compared through the combination of their Young’s modulus, yield strength, remanent induction, and coercive force. Several potential applications requiring both mechanical and magnetic properties are reported.
TiO2-Seeded Hydrothermal Growth of Spherical BaTiO3 Nanocrystals for Capacitor Energy-Storage Application
Authors: Li Ming , Gu Lulu , Li Tao , Hao Shiji , Tan Furui , Chen Deliang , Zhu Deliang , Xu Yongjun , Sun Chenghua , Yang Zhenyu
Published: March 2020

Simple but robust growth of spherical BaTiO3 nanoparticles with uniform nanoscale sizes is of great significance for the miniaturization of BaTiO3-based electron devices. This paper reports a TiO2-seeded hydrothermal process to synthesize spherical BaTiO3 nanoparticles with a size range of 90–100 nm using TiO2 (Degussa) and Ba(NO3)2 as the starting materials under an alkaline (NaOH) condition. Under the optimum conditions ([NaOH] = 2.0 mol L−1, RBa/Ti = 2.0, T = 210 °C and t = 8 h), the spherical BaTiO3 nanoparticles obtained exhibit a narrow size range of 91 ± 14 nm, and the corresponding BaTiO3/polymer/Al film is of a high dielectric constant of 59, a high break strength of 102 kV mm−1, and a low dielectric loss of 0.008. The TiO2-seeded hydrothermal growth has been proved to be an efficient process to synthesize spherical BaTiO3 nanoparticles for potential capacitor energy-storage applications.
Purification of Curcumin from Ternary Extract-Similar Mixtures of Curcuminoids in a Single Crystallization Step
Authors: Horosanskaia Elena , Yuan Lina , Seidel-Morgenstern Andreas , Lorenz Heike
Published: March 2020

Crystallization-based separation of curcumin from ternary mixtures of curcuminoids having compositions comparable to commercial extracts was studied experimentally. Based on solubility and supersolubility data of both, pure curcumin and curcumin in presence of the two major impurities demethoxycurcumin (DMC) and bis(demethoxy)curcumin (BDMC), seeded cooling crystallization procedures were derived using acetone, acetonitrile and 50/50 (wt/wt) mixtures of acetone/2-propanol and acetone/acetonitrile as solvents. Starting from initial curcumin contents of 67–75% in the curcuminoid mixtures single step crystallization processes provided crystalline curcumin free of BDMC at residual DMC contents of 0.6–9.9%. Curcumin at highest purity of 99.4% was obtained from a 50/50 (wt/wt) acetone/2-propanol solution in a single crystallization step. It is demonstrated that the total product yield can be significantly enhanced via addition of water, 2-propanol and acetonitrile as anti-solvents at the end of a cooling crystallization process.
Assessment of DCE Utility for PCa Diagnosis Using PI-RADS v2.1: Effects on Diagnostic Accuracy and Reproducibility
Authors: Brancato Valentina , Di Costanzo Giuseppe , Basso Luca , Tramontano Liberatore , Puglia Marta , Ragozzino Alfonso , Cavaliere Carlo
Published: March 2020

The role of dynamic contrast-enhanced-MRI (DCE-MRI) for Prostate Imaging-Reporting and Data System (PI-RADS) scoring is a controversial topic. In this retrospective study, we aimed to measure the added value of DCE-MRI in combination with T2-weighted (T2W) and diffusion-weighted imaging (DWI) using PI-RADS v2.1, in terms of reproducibility and diagnostic accuracy, for detection of prostate cancer (PCa) and clinically significant PCa (CS-PCa, for Gleason Score ≥ 7). 117 lesions in 111 patients were identified as suspicion by multiparametric MRI (mpMRI) and addressed for biopsy. Three experienced readers independently assessed PI-RADS score, first using biparametric MRI (bpMRI, including DWI and T2W), and then multiparametric MRI (also including DCE). The inter-rater and inter-method agreement (bpMRI- vs. mpMRI-based scores) were assessed by Cohen’s kappa (κ). Receiver operating characteristics (ROC) analysis was performed to evaluate the diagnostic accuracy for PCa and CS-PCa detection among the two scores. Inter-rater agreement was excellent for the three pairs of readers (κ ≥ 0.83), while the inter-method agreement was good (κ ≥ 0.73). Areas under the ROC curve (AUC) showed similar high-values (0.8 ≤ AUC ≤ 0.85). The reproducibility of PI-RADS v2.1 scoring was comparable and high among readers, without relevant differences, depending on the MRI protocol used. The inclusion of DCE did not influence the diagnostic accuracy.
Detrending the Waveforms of Steady-State Vowels
Authors: Van Soom Marnix , de Boer Bart
Published: March 2020

Steady-state vowels are vowels that are uttered with a momentarily fixed vocal tract configuration and with steady vibration of the vocal folds. In this steady-state, the vowel waveform appears as a quasi-periodic string of elementary units called pitch periods. Humans perceive this quasi-periodic regularity as a definite pitch. Likewise, so-called pitch-synchronous methods exploit this regularity by using the duration of the pitch periods as a natural time scale for their analysis. In this work, we present a simple pitch-synchronous method using a Bayesian approach for estimating formants that slightly generalizes the basic approach of modeling the pitch periods as a superposition of decaying sinusoids, one for each vowel formant, by explicitly taking into account the additional low-frequency content in the waveform which arises not from formants but rather from the glottal pulse. We model this low-frequency content in the time domain as a polynomial trend function that is added to the decaying sinusoids. The problem then reduces to a rather familiar one in macroeconomics: estimate the cycles (our decaying sinusoids) independently from the trend (our polynomial trend function); in other words, detrend the waveform of steady-state waveforms. We show how to do this efficiently.
An Entropy-Based Approach to Portfolio Optimization
Authors: Mercurio Peter Joseph , Wu Yuehua , Xie Hong
Published: March 2020

This paper presents an improved method of applying entropy as a risk in portfolio optimization. A new family of portfolio optimization problems called the return-entropy portfolio optimization (REPO) is introduced that simplifies the computation of portfolio entropy using a combinatorial approach. REPO addresses five main practical concerns with the mean-variance portfolio optimization (MVPO). Pioneered by Harry Markowitz, MVPO revolutionized the financial industry as the first formal mathematical approach to risk-averse investing. REPO uses a mean-entropy objective function instead of the mean-variance objective function used in MVPO. REPO also simplifies the portfolio entropy calculation by utilizing combinatorial generating functions in the optimization objective function. REPO and MVPO were compared by emulating competing portfolios over historical data and REPO significantly outperformed MVPO in a strong majority of cases.
Assessing and Predicting the Water Resources Vulnerability under Various Climate-Change Scenarios: A Case Study of Huang-Huai-Hai River Basin, China
Authors: Chen Yan , Feng Yazhong , Zhang Fan , Yang Fan , Wang Lei
Published: March 2020

The Huang-Huai-Hai River Basin plays an important strategic role in China’s economic development, but severe water resources problems restrict the development of the three basins. Most of the existing research is focused on the trends of single hydrological and meteorological indicators. However, there is a lack of research on the cause analysis and scenario prediction of water resources vulnerability (WRV) in the three basins, which is the very important foundation for the management of water resources. First of all, based on the analysis of the causes of water resources vulnerability, this article set up the evaluation index system of water resource vulnerability from three aspects: water quantity, water quality and disaster. Then, we use the Improved Blind Deletion Rough Set (IBDRS) method to reduce the dimension of the index system, and we reduce the original 24 indexes to 12 evaluation indexes. Third, by comparing the accuracy of random forest (RF) and artificial neural network (ANN) models, we use the RF model with high fitting accuracy as the evaluation and prediction model. Finally, we use 12 evaluation indexes and an RF model to analyze the trend and causes of water resources vulnerability in three basins during 2000–2015, and further predict the scenarios in 2020 and 2030. The results show that the vulnerability level of water resources in the three basins has been improved during 2000–2015, and the three river basins should follow the development of scenario 1 to ensure the safety of water resources. The research proved that the combination of IBDRS and an RF model is a very effective method to evaluate and forecast the vulnerability of water resources in the Huang-Huai-Hai River Basin.
Semantic and Generalized Entropy Loss Functions for Semi-Supervised Deep Learning
Authors: Gajowniczek Krzysztof , Liang Yitao , Friedman Tal , Ząbkowski Tomasz , Van den Broeck Guy
Published: March 2020

The increasing size of modern datasets combined with the difficulty of obtaining real label information (e.g., class) has made semi-supervised learning a problem of considerable practical importance in modern data analysis. Semi-supervised learning is supervised learning with additional information on the distribution of the examples or, simultaneously, an extension of unsupervised learning guided by some constraints. In this article we present a methodology that bridges between artificial neural network output vectors and logical constraints. In order to do this, we present a semantic loss function and a generalized entropy loss function (Rényi entropy) that capture how close the neural network is to satisfying the constraints on its output. Our methods are intended to be generally applicable and compatible with any feedforward neural network. Therefore, the semantic loss and generalized entropy loss are simply a regularization term that can be directly plugged into an existing loss function. We evaluate our methodology over an artificially simulated dataset and two commonly used benchmark datasets which are MNIST and Fashion-MNIST to assess the relation between the analyzed loss functions and the influence of the various input and tuning parameters on the classification accuracy. The experimental evaluation shows that both losses effectively guide the learner to achieve (near-) state-of-the-art results on semi-supervised multiclass classification.
Weighted Mean Squared Deviation Feature Screening for Binary Features
Authors: Wang Gaizhen , Guan Guoyu
Published: March 2020

In this study, we propose a novel model-free feature screening method for ultrahigh dimensional binary features of binary classification, called weighted mean squared deviation (WMSD). Compared to Chi-square statistic and mutual information, WMSD provides more opportunities to the binary features with probabilities near 0.5. In addition, the asymptotic properties of the proposed method are theoretically investigated under the assumption log p = o ( n ) . The number of features is practically selected by a Pearson correlation coefficient method according to the property of power-law distribution. Lastly, an empirical study of Chinese text classification illustrates that the proposed method performs well when the dimension of selected features is relatively small.
The Emergence of Integrated Information, Complexity, and ‘Consciousness’ at Criticality
Authors: Popiel Nicholas J.M. , Khajehabdollahi Sina , Abeyasinghe Pubuditha M. , Riganello Francesco , Nichols Emily S. , Owen Adrian M. , Soddu Andrea
Published: March 2020

Integrated Information Theory (IIT) posits that integrated information ( Φ ) represents the quantity of a conscious experience. Here, the generalized Ising model was used to calculate Φ as a function of temperature in toy models of fully connected neural networks. A Monte–Carlo simulation was run on 159 normalized, random, positively weighted networks analogous to small five-node excitatory neural network motifs. Integrated information generated by this sample of small Ising models was measured across model parameter spaces. It was observed that integrated information, as an order parameter, underwent a phase transition at the critical point in the model. This critical point was demarcated by the peak of the generalized susceptibility (or variance in configuration due to temperature) of integrated information. At this critical point, integrated information was maximally receptive and responsive to perturbations of its own states. The results of this study provide evidence that Φ can capture integrated information in an empirical dataset, and display critical behavior acting as an order parameter from the generalized Ising model.
Landauer Principle and General Relativity
Authors: Herrera Luis
Published: March 2020

We endeavour to illustrate the physical relevance of the Landauer principle applying it to different important issues concerning the theory of gravitation. We shall first analyze, in the context of general relativity, the consequences derived from the fact, implied by Landauer principle, that information has mass. Next, we shall analyze the role played by the Landauer principle in order to understand why different congruences of observers provide very different physical descriptions of the same space-time. Finally, we shall apply the Landauer principle to the problem of gravitational radiation. We shall see that the fact that gravitational radiation is an irreversible process entailing dissipation, is a straightforward consequence of the Landauer principle and of the fact that gravitational radiation conveys information. An expression measuring the part of radiated energy that corresponds to the radiated information and an expression defining the total number of bits erased in that process, shall be obtained, as well as an explicit expression linking the latter to the Bondi news function.
Investigation of Early Warning Indexes in a Three-Dimensional Chaotic System with Zero Eigenvalues
Authors: Chen Lianyu , Nazarimehr Fahimeh , Jafari Sajad , Tlelo-Cuautle Esteban , Hussain Iqtadar
Published: March 2020

A rare three-dimensional chaotic system with all eigenvalues equal to zero is proposed, and its dynamical properties are investigated. The chaotic system has one equilibrium point at the origin. Numerical analysis shows that the equilibrium point is unstable. Bifurcation analysis of the system shows various dynamics in a period-doubling route to chaos. We highlight that from the evaluation of the entropy, bifurcation points can be predicted by identifying early warning signals. In this manner, bifurcation points of the system are analyzed using Shannon and Kolmogorov-Sinai entropy. The results are compared with Lyapunov exponents.
No-Reference Image Quality Assessment Based on Dual-Domain Feature Fusion
Authors: Cui Yueli
Published: March 2020

Image quality assessment (IQA) aims to devise computational models to evaluate image quality in a perceptually consistent manner. In this paper, a novel no-reference image quality assessment model based on dual-domain feature fusion is proposed, dubbed as DFF-IQA. Firstly, in the spatial domain, several features about weighted local binary pattern, naturalness and spatial entropy are extracted, where the naturalness features are represented by fitting parameters of the generalized Gaussian distribution. Secondly, in the frequency domain, the features of spectral entropy, oriented energy distribution, and fitting parameters of asymmetrical generalized Gaussian distribution are extracted. Thirdly, the features extracted in the dual-domain are fused to form the quality-aware feature vector. Finally, quality regression process by random forest is conducted to build the relationship between image features and quality score, yielding a measure of image quality. The resulting algorithm is tested on the LIVE database and compared with competing IQA models. Experimental results on the LIVE database indicate that the proposed DFF-IQA method is more consistent with the human visual system than other competing IQA methods.
On the Rate-Distortion Function of Sampled Cyclostationary Gaussian Processes
Authors: Abakasanga Emeka , Shlezinger Nir , Dabora Ron
Published: March 2020

Man-made communications signals are typically modelled as continuous-time (CT) wide-sense cyclostationary (WSCS) processes. As modern processing is digital, it is applied to discrete-time (DT) processes obtained by sampling the CT processes. When sampling is applied to a CT WSCS process, the statistics of the resulting DT process depends on the relationship between the sampling interval and the period of the statistics of the CT process: When these two parameters have a common integer factor, then the DT process is WSCS. This situation is referred to as synchronous sampling. When this is not the case, which is referred to as asynchronous sampling, the resulting DT process is wide-sense almost cyclostationary (WSACS). The sampled CT processes are commonly encoded using a source code to facilitate storage or transmission over wireless networks, e.g., using compress-and-forward relaying. In this work, we study the fundamental tradeoff between rate and distortion for source codes applied to sampled CT WSCS processes, characterized via the rate-distortion function (RDF). We note that while RDF characterization for the case of synchronous sampling directly follows from classic information-theoretic tools utilizing ergodicity and the law of large numbers, when sampling is asynchronous, the resulting process is not information stable. In such cases, the commonly used information-theoretic tools are inapplicable to RDF analysis, which poses a major challenge. Using the information-spectrum framework, we show that the RDF for asynchronous sampling in the low distortion regime can be expressed as the limit superior of a sequence of RDFs in which each element corresponds to the RDF of a synchronously sampled WSCS process (yet their limit is not guaranteed to exist). The resulting characterization allows us to introduce novel insights on the relationship between sampling synchronization and the RDF. For example, we demonstrate that, differently from stationary processes, small differences in the sampling rate and the sampling time offset can notably affect the RDF of sampled CT WSCS processes.
The State of British Columbia’s Forests: A Global Comparison
Authors: Gilani Haris R. , Innes John L.
Published: March 2020

The Forest Resources Assessment 2015 is a comprehensive dataset from the Food and Agriculture Organization of the United Nations (FAO), which provides the opportunity to explore some of the emerging topics related to sustainable forest management. This paper assesses how forests in British Columbia, Canada, compare globally on several key sustainable forest management parameters in four domains—biophysical indicators and legal framework, management plans, data management, and stakeholder involvement. The comparison was done against eight jurisdictions, namely Australia, China, Japan, the European Union, New Zealand, the Russian Federation and the USA. To accomplish our objectives, country-specific data on sustainable forest management parameters were extracted from the 2015 FAO’s Global Forest Resources Assessment (FRA). Data specific to B.C. were sourced from Canada’s National Forest Inventory, and National Forest Database. Our results showed that British Columbia (B.C.) has one of the highest proportions of land covered with forests (57%) among all jurisdictions. The total forest area in B.C. has remained stable at around 55 million ha. The current rate of deforestation (6200 ha per year) is among the lowest in all jurisdictions. Data on the extent of primary forests in B.C. is unavailable. However, 22.6 million ha (41% of B.C.′s forests) have been classified as old growth forests (using a definition unique to B.C.). B.C. is the leading provincial forest producer by volume, and produced 67.97 million m3 of roundwood in 2015. With approximately 11 billion m3 of standing timber, roundwood production volume has held steady since 1990. In British Columbia, the National Forest Inventory—British Columbia Program (NFI-B.C.) is used to track and monitor the current status of the forests. It involves both ground plots and remote sensing. The most recent B.C. State of the Forests is one of the most comprehensive reports among all jurisdictions, using 24 topic areas, with each topic comprising several indicators of sustainable forest management. We conclude that British Columbia ranks high among other jurisdictions on several key sustainable forest management parameters with legislation and forest management regimes aiming to meet the environmental, social and economic needs of current and future generations.