Miracle-dz/UniFAR-FTUs huggingface dataset:
Quantum Hall effect in graphene for resistance metrology : Disorder and quantization

The quantum Hall effect (QHE) observed in two dimensional electron gas placed at low temperature and under a strong perpendicular magnetic field, has revolutionized the resistance metrology since its discovery in 1980 by Klaus von Klitzing. It provides a representation of the ohm based on the Planck constant and the electron charge only. In 2004, graphene, a purely two dimensional arrangement of carbon atoms in an honeycomb lattice, where the charge carriers behave as Dirac fermions, has revealed a new flavor of the QHE. From the metrological point of view the QHE in graphene is very promising since it is much more robust than the effect appearing in conventional semiconductors and it could lead to a more convenient resistance standard operating at higher temperature and lower magnetic induction which is an advantage for a broader dissemination of a precise standard towards industrial end-users. In this manuscript, a complete study about the impact in the QHE regime of line defects such as wrinkles or grain boundaries, ubiquitous in graphene grown by chemical vapor deposition on metal is treated. We show that these line defects lead to a non conventional dissipation mechanism that jeopardize the quantum Hall effect accuracy pointing to the use of wrinkle-free monocrystals for further metrological studies. The second part of my manuscript is focused on monolayer graphene grown by chemical vapor deposition on silicon carbide. We precisely compared the Hall resistance of the graphene sample from 10 T to 19 T at the temperature of 1.4 K with a GaAs/AlGaAs resistance standard with a relative uncertainty of ( -2 ± 4 ) × 10⁻¹⁰. For the first time a graphene-based standard was able to operate in the same temperature and magnetic field conditions as semiconductor-based one, furthermore, on a magnetic range more than ten times larger. We thus made a careful study of the dissipation mechanisms taking place in this sample and measured precisely the magnitude of the localization length in the QHE regime that saturate interestingly at the extension of the charge carrier wavefunction itself, opening interesting questions about the close link between Hall quantization and localization physics in graphene grown on SiC. Finally in a second sample grown using the same technique we precisely compared the Hall resistance of the graphene sample and a GaAs/AlGaAs resistance standard that turned out to be in agreement at the metrological level for magnetic fields as low as 3.5 T current as high as 500 µA and temperature as high 9 K. This paves the way for the realization of easy to use quantum Hall resistance standards made out of graphene.
Comparison of Acidic and Enzymatic Pectin Extraction from Passion Fruit Peels and Its Gel Properties

The influences of extractor concentration, extraction temperature and time on the yield of pectin and degree of esterification (DE) were investigated by the acidic and enzymatic extraction methods. Citric acid and Celluclast were selected as pectin extractors for environmentally friendly reasons. The peels of yellow passion fruit using the acidic and enzymatic extraction methods gave pectin yield of 7.16 and 7.12%, and DE of 71.02 and 85.45% in the optimized condition of extraction time of 102 min with citric acid concentration of 0.19% (w/w) at 75C and Celluclast concentration of 1.67% (w/w) at 61.11C, respectively. The enzymatic extraction method has greater capability of producing high methoxyl pectin. The morphological features of fruit peel powder and the extracted pectin examined by scanning electron microscopy suggested that the nanostructure of wet passion fruit pectin was dependable on the type of extraction process. The formed pectin gel also has pseudoplastic liquid behavior and its viscosity was greatly affected by sugar. Pectin has been intensively used as natural gelling agent and stabilizer to alter rheological properties in food ingredients by most food processing industries to achieve desired textural quality. Pectin could be recovery from fruit wastes. The conversion of passion fruit peel into pectin offers great scope for utilization. Citric acid and enzymatic extraction methods are effectively used for pectin extraction which may be of interest by pectin industry and consumer with these eco-friendly processing technology with no using harmful chemicals. Furthermore, scientific work of this study such as the optimized condition, morphological features of extracted pectin and pectin gel formation contributes valuable information on pectin, which could be beneficial for pectin industry improving the process quality of pectin as well as process profitability.
The Index-pm project : health risks from exposure to indoor particulate matter

This article illustrates the methods and findings of as- sessing the health risks of exposure to indoor particulate matter in the frame of the European INDEX-PM project (12). The evaluation was performed by taking into ac- count all sources and types of indoor particulate matter, and distinguishing it to particulate matter (PM) from outdoor origin, from indoor combustion, environmental tobacco smoke, indoor air particles of biological origin, indoor resuspended mineral dust particles, semi-volatile organic compounds, as well as secondary particles gener- ated by indoor air chemistry. It comprises an outline of a state-of-the-art review of existing exposure and dose- response data of indoor PM and focuses at deriving general and by-source risk characterisation and risk management options for reducing potential health effects associated with exposure to indoor PM.
Raman spectroscopy of boron carbides and related boron‐containing materials

Raman spectra of crystalline boron, boron carbide, boron arsenide (B12As2), and boron phosphide (B12P2) are reported. The spectra are compared with other boron‐containing materials containing the boron icosahedron as a structural unit. The spectra exhibit similar features some of which correlate with the structure of the icosahedral units of the crystals. The highest Raman lines appear to be especially sensitive to the B‐B distance in the polar triangle of the icosahedron. Such Raman structural markers are potentially useful in efforts to tailor electronic properties of these high temperature semiconductors and thermoelectrics.Raman spectroscopy is also useful in characterizing methods of preparation of boron‐based materials. For example, inclusions of carbonaceous material in the boron carbides can be detected by the presence of two broad Raman lines 1370 and 1580 cm−1. In the hot‐pressed samples that exhibited the lines the carbonaceous material is amorphous and much like carbon black or pyrolytic glass.
Propagation of signals in the chains of bi-stable elements

This article is devoted to treating the behavior of systems composed of an ensemble of bi-stable cells which are capable to write and store information and are connected with similar cells placed along one dimensional direction so as information can propagate along this direction in wave form. Basic equations were derived and solved. Waves of information are related to the change in the entropy of the environment. The results of this article clarify the well known Landauer’s principle.
Ta2O5 polymorphs: Structural motifs and dielectric constant from first principles

Using large-scale simulations based on density-functional theory we determine the structural properties of several polymorphs of tantalia, their vibrational spectra and dielectric properties. Our calculations indicate that structurally distinct configurations can coexist, having coordination polyhedra that are dissimilar or have different relative arrangements. Interpolyhedra vibrations are discovered to be responsible for sizable changes of the static dielectric constant from one polymorph to the other. Our results for the dielectric constant (both at high and low frequency) are in excellent agreement with experiment and provide an explanation for the different measured values and their claimed dependence on growth conditions.
Color Changes Caused by Conformational Polymorphism: Optical-Crystallography, Single-Crystal Spectroscopy, and Computational Chemistry

5-Methyl-2-[(2-nitrophenyl)amino]-3-thiophenecarbonitrile (1) crystallizes as seven conformational polymorphs of red, orange, and yellow colors. Comparable thermodynamic stability of the polymorphs enables the solution of six crystal structures, a number unmatched by current entries in the Cambridge Structural Database, making 1 well suited for structure−property studies. The different crystal colors of 1 have been studied using optical crystallography, polarized single-crystal absorption spectroscopy and computational methods. Different crystal colors (“color polymorphism”) are well explained by the conformational differences between polymorphs, which cause varying degrees of π-conjugation between the o-nitroaniline chromophore and the thiophene group. The isolation of different conformers in crystal polymorphs permits an evaluation of computational models of electronic structures and transitions through observed spectral properties. The newly matured Time Dependent Density Functional Theory gave the bes.
Synthesis of molecular-gripper-type dynamic receptors and STM-imaging of self-assembled monolayers on gold

Dynamic receptors capable of undergoing large temperature or pH-dependent conformational changes were functionalised with dialkyl thioether legs and adsorbed on Au(111) single crystal surfaces to give self-assembled monolayers (SAMs). The SAMs were characterised by ellipsometry and contact angle measurements. Imaging by scanning tunnelling microscopy (STM) revealed well-ordered monolayers at molecular resolution.
Role of Repulsive Forces in Determining the Equilibrium Structure of Simple Liquids

The different roles the attractive and repulsive forces play in forming the equilibrium structure of a Lennard‐Jones liquid are discussed. It is found that the effects of these forces are most easily separated by considering the structure factor (or equivalently, the Fourier transform of the pair‐correlation function) rather than the pair‐correlation function itself. At intermediate and large wave vectors, the repulsive forces dominate the quantitative behavior of the liquid structure factor. The attractions are manifested primarily in the small wave vector part of the structure factor; but this effect decreases as the density increases and is almost negligible at reduced densities higher than 0.65. These conclusions are established by considering the structure factor of a hypothetical reference system in which the intermolecular forces are entirely repulsive and identical to the repulsive forces in a Lennard‐Jones fluid. This reference system structure factor is calculated with the aid of a simple but accurate approximation described herein. The conclusions lead to a very simple prescription for calculating the radial distribution function of dense liquids which is more accurate than that obtained by any previously reported theory. The thermodynamic ramifications of the conclusions are presented in the form of calculations of the free energy, the internal energy (from the energy equation), and the pressure (from the virial equation). The implications of our conclusions to perturbation theories for liquids and to the interpretation of x‐ray scattering experiments are discussed.
Karakterisasi dan Aktivitas Antioksidan Tepung Sagu Baruk (Arenga microcarpha)

Tujuan penelitian ini adalah untuk mempelajari karakteristik kimia tepung sagu baruk yang mengandung senyawa fitokimia dan mempelajari aktivitas antioksidan dari ekstrak tepung sagu baruk. Tepung sagu baruk diekstrak dengan pelarut etanol 50% dengan cara maserasi selama 24 jam. Setelah itu, tepung sagu diuji proksimat, ekstrak dianalisis kandungan fitokimia fenolik, flavonoid dan tanin terkondensasi. Pengujian aktivitas antioksidan menggunakan radikal bebas DPPH dan daya reduksi dengan spektrofotometer UV/Vis. Hasil penelitian menunjukkan pada pengujian proksimat bahwa tepung tepung sagu baruk memenuhi syarat Standar Nasional Indonesia, tetapi berbeda dengan kadar serat kasar. Total kandungan fenolik dan flavonoid menunjukkan bahwa tepung sagu akuades (SA) lebih tinggi daripada tepung sagu komersial (TSBK). Hasil radikal bebas sagu tepung sagu SA lebih tinggi dari TSBK sama halnya dengan kemampuan daya reduksi SA jauh lebih tinggi dari TSBK. Hasil penelitian ini menyimpulkan bahwa tepung sagu baruk memiliki kandungan fitokimia fenolik dan flavonoid yang dapat berpotensi sebagai antioksidan. Objectives of this research were to study the chemical characteristics of sago baruk flour containing phytochemicals and antioxidant activity of sago baruk flour extract. Sago baruk flour was extracted with 50% ethanol by maceration for 24 hours. Afterward, sago flour was tested for proximate and the extract was analyzed for phenolic, flavonoids, and condensed tanin. DPPH free radical was used to examine antioxidant activity and spectrophotometry method was used to determine the reduction ability. The result for proximate test showed that sago flour extract meets Indonesian Nasional Standard requirements. Total phenolic and flavonoid contents in the flour extracted with aquadest (SA) were higher than that in commercial flour (TSBK). Free radical scavenging activity of sago flour SA was higher than that of TSBK, as well as the reduction ability of SA that was much higher than of TSBK. It was concluded that sago baruk flour possess phytochemical content of phenolic and flavonoid which were potential as antioxidant.
Assessing the environmental impact of tourism development: the use of the Delphi technique

This paper reports the development and application of a methodology for the environmental impact assessment of tourism projects. It reviews the background literature on tourism related impacts and the wider problems of environmental impact assessment, including issues associated with measurement. The Delphi technique is then identified as a potentially valuable tool for the identification and assessment of environmental impacts. The findings of the application of the developed methodology to a specific tourism project, namely Salts Mill, Bradford (UK) are presented. An assessment is then made of the methodology along with an outline for further refinement and testing of the approach.
Preparation and Evaluation of the Oxidation Ability of Hematin-Appended 6-Amino-6-Deoxycellulose

Abstract The reaction of 6-amino-6-deoxycelluloe (1) with hematin in the presence of N,N′-carbonyldiimidazole and 1,8-diazabicyclo[5.4. 0]undec-7-ene in N,N-dimethylformamide at 50°C for four days afforded hematin-appended 6-aminocellulose (2). Compound 2 was more stable than hematin, and retained the oxidation activity of hematin, even after being treated at 100°C for 3 h. Compound 2 showed good guaiacol oxidation activity in an aqueous 80% AcOH solution (pH 1.5), whereas hematin and horseradish peroxidase showed very low oxidation activities under the same conditions, suggesting that compound 2 is a useful biomimetic catalyst. However, no asymmetric induction was achieved in the catalytic oxidation of sinapyl alcohol (3) using compound 2.
Novel fluorescent matrix embedded carbon quantum dots for the production of stable gold and silver hydrosols

A facile one step route has been developed for the synthesis of highly fluorescent matrix embedded carbon quantum dots (MCQDs) by the assistance of microwave irradiation. The material shows a homogeneous distribution of carbon quantum dots throughout the surfaces of the carbon matrices with an average size of 1 to 3 nm. The synthetic MCQDs can be employed as excellent catalysts during the synthesis of gold and silver nanoparticles.
Positron Lifetime Distributions and Free Volume Parameters of PEO/PMMA Blends Determined with the Maximum Entropy Method

The temperature dependence of the average free volume hole size and its distribution in blends of poly(methyl methacrylate) and poly(ethylene oxide) were studied by positron annihilation lifetime spectroscopy. Measurements at room temperature, 70 °C, and 110 °C all indicate that the average ortho-positronium lifetime (τ3), and thus the free volume hole size of the blends, shows a positive deviation from additivity of the values of the pure components. Mean ortho-positronium (o-Ps) lifetimes and intensities were calculated with the POSITRONFIT program, while o-Ps lifetime distributions were obtained from evaluations made with a recently introduced program based on Bayes' theorem and the maximum entropy principle. o-Ps lifetime distributions were successfully calculated for all measured spectra and offer valuable additional information about the structure of the studied blends. At 70 °C, the distributions seem to reflect the lifetimes in a blend of binodal composition. Large differences in width of the o-Ps.
Protective effect of hypoxic preconditioning against cerebral ischemic injury induced by acute cerebral infarction in mice

Objective To observe the protective effect of hypoxic preconditioning against cerebral ischemic injury induced by acute cerebral infarction in mice. Methods Blb/c mice were randomized into normal control, sham-operated, acute cerebral infarction (CI), and hypoxic preconditioning with CI (HP+CI) groups. In the latter two groups, acute cerebral cortical infarction was induced photochemically by cold light exposure of the brain tissue following intravenous Rose Bengal injection. The mice in the sham-operated group received only cold light exposure without Rose Bengal injection. Behavioral test, immunofluorescence assay and confocal laser scanning microscopy were performed to evaluate the neurological deficits of the mice and assess the cell apoptosis, and the cerebral infarction volume was measured. Results No infarct was found in the normal control and sham-operated groups, whereas obvious isehemic infarction foci were found in CI and HP+CI groups, but the infarction volume was significantly smaller in HP+CI group (P<0.05). The mice in the normal control and sham-operated groups presented with no neurological impairment, but in CI and HP+CI groups, obvious symptoms of neurological impairment were observed with lowered neurological scores. The neurological scores were significantly higher in HP+CI group than in CI group (P<0.05). Occasional apoptotic cells were found in the normal control and sham-operated groups, while in the other two groups, the TUNEL-positive cell number increased significantly. The apoptotic cell number was significantly smaller in HP+CI group than in CI group (P<0.05). Conclusion Hypoxic preconditioning may protect against cerebral ischemic injury induced by acute cerebral infarction in mice possibly by reducing the cerebral infarction volume and cell apoptosis. Key words: Hypoxic preconditioning; Acute cerebral infarction; Cell apoptosis
Chemistry of PCB's

The literature on chlorinated biphenyl is growing rapidly. Review articles on PCB's cited in this book usually contained a section on the toxicity of PCB. The structure and nomenclature are detailed. The chapters and topics included are (1) commercial PCB preparations: properties and compositions, (2) synthesis of chlorobiphenyls, (3) chemical reactions of chlorobiphenyls, (4) photodegradation of chlorobiphenyls, (5) metabolism of chlorobiphenyls, (5) mass spectroscopy of chlorobiphenyls, (6) nuclear magnetic resonance of chlorobiphenyls, (7) ultraviolet spectroscopy of chlorobiphenyls, (8) infrared spectrometry of chlorobiphenyls, (9) determination of chlorobiphenyls, and (10) recent developments. (DP)
Alternatives use of somatic cell counts in genetic selection for mastitis resistance

Various alternatives in analyzing somatic cell counts (SCC) as indirect indicator of resistance of mastitis are discussed by integrating knowledge of the dynamics of the infection and statistical methods used in quantitative genetics and epidemiological research. This is done by (1) defining various measures of SCC, (2) identifying non genetic factors of SCC variation, and (3) proposing a new alternative to analyze the data. ___________________________________________________________________________________
The Validity and Reliability on Korean Version of the Falls Behavioural (FaB) Scale for the Older Person

The aim of this study FaB was translated into Korean by systematic translation process. The content validity and the reliability were tested with Korean version of FaB. The translation was performed using direct and backward translation process. The content validity was tested with the 30 expert panels by Delphi method. The translated Korean version of FaB was performed to 109 community dwelling elderly person with and without disability. The FaB was translated in Korean. 11 items among total 30 items were judged as culturally inappropriate(CVR=–0.20∼0.80). The internal consistency of Korean version of Received(January 2, 2018), Review Result(January 10, 2018) Accepted(March 9, 2018), Published(April 30, 2018) 1 27610 Associate Professor, Dept. Occupational therapy, FarEast University, Wangjang-ri, Eumseong-gun, Chungcheongbuk-do, Korea email: catharina.ymj@gmail.com 2 (Corresponding Author)27610 Assistant Professor, Dept. Occupational therapy, Kangwon National University, Hwangjo-gil, Dogye-eup, samcheok-si, Kangwon-do, Korea email: bluecatchh@naver.com The Validity and Reliability on Korean Version of the Falls Behavioural (FaB) Scale for the Older Person Copyright c 2018 HSST 668 FaB was 0.78 (Cronbach’s ɑ). The reliability of Korean version of FaB is relatively high to be used in clinic. However, the 11 items over total 30 items was judged culturally inappropriate to apply Korean elderly by expert Delphi method. FaB is the assessment to evaluate behavioral factors related to falls, the behaviors are highly influenced by social and cultural context. Therefore, it is necessary to develop new items on Korean version of FaB which are culturally valid in the future study.
Swelling and release kinetics of larvicide‐containing chitosan/cashew gum beads

A new pesticide formulation (bead) based on chitosan (CH) and cashew gum (CG) containing dichlorvos [2,2-dichlorovinyldimethyl phosphate (DDVP)] was prepared and investigated as a larvicide for Aedes aegypti control. Beads were characterized with respect to their size, shape, larvicide loading, swelling, and in vitro and in vivo release kinetics. CH and CH/CG beads were loaded with DDVP from 5.15 to 71.4%. In the first hour, the in vitro release was similar for CH and CH/CG beads, faster release being observed after 5 h for CH/CG beads; at equilibrium (30 h), CH beads released up to 55% of the larvicide, and CH/CG beads reached 66%. The data were fitted to a mathematical model, being in good agreement with the literature. In vivo release showed that CH/CG beads reached a plateau after 30 h, resulting in a highest mortality of approximately 60%, whereas CH beads killed only 42% of the larvae by 30 h and seemed not to have released their whole larvicide content even after 72 h. The DDVP lethal dose for 50% mortality was found to be 0.01 ± 0.002 ppm; the persistence studies revealed that after 168 h, 42.5% larval mortality was obtained by CH beads, and only approximately half of that was obtained by CH/CG beads. DDVP-loaded beads were effective up to 336 h. It could be concluded that beads containing DDVP at an average concentration of 7.2 ppm could provide good larval control up to 7 days. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 395–400, 2006