Miracle-dz/UniFAR-FTUs huggingface dataset:
Towards understanding of birds magnetoreceptor mechanism

In the present letter we suggest a new theoretical model for a quantitative description of the magnetoreception mechanism in birds. The considered mechanism involves two types of iron minerals (magnetite and maghemite) which were found in subcellular compartments within sensory dendrites of the upper beak of several bird species. The analysis of forces acting between the iron particles shows that the orientation of the external geomagnetic field can significantly change the probability of the mechanosensitive ion channels opening and closing. The performed theoretical analysis shows that the suggested magnetoreceptor system might be a sensitive biological magnetometer providing an essential part of the magnetic map for navigation.
Large-Scale Electronic Transport Calculations of Finite-Length Carbon Nanotubes Bridged between Graphene Electrodes with Lithium-Intercalated Contact

We perform density-functional-theory-based large-scale calculations of finite-length carbon nanotubes with caps bridged between graphene electrodes. The electronic transport properties vary with the length of the nanotubes and the contact structure. Despite the use of thin nanotubes expected to show n-type behavior, the Fermi level of the shorter nanotubes is uniformly pinned to the cap state, forming a large conduction gap. Although the longer nanotubes still have a medium conduction gap after forming a Schottky-like contact, the lithium intercalation in the contact area brings about a good ohmic property due to not only doping but also the orbital hybridization.
Molecular Dynamics Simulation for the Mixture of Water and an Ice Nucleus

We have carried out a molecular dynamics simulation for the melting and solidification of ice nucleus. An ice crystal was formed by controlling the displacement and velocity of each molecule. Part of the ice was melted by supplying energy to it in order to produce a mixture of an ice nucleus and surrounding water at approximately freezing point. By using this mixture, a mixture of an ice nucleus and supercooled water was made. It was found that the time scale for the correlation between the potential energy and the rotational component of the kinetic energy was different from that of the correlation between the potential energy and the translational component of the kinetic energy. Also, it was predicted that the ice nucleus received forces whose directions were not exactly the same as those of the growth of ice crystal.
Layered Silicate Nanocomposites Based on Various High-Functionality Epoxy Resins: The Influence of Cure Temperature on Morphology, Mechanical Properties, and Free Volume

This paper investigates the relationship between cure temperature, morphology, and mechanical properties of di-, tri-, and tetrafunctional high-performance, epoxy layered-silicate nanocomposites. Wide-angle X-ray analysis (XRD) was carried out at different stages of cure to monitor organoclay exfoliation kinetics. It was found that some (small) degree of conversion was required to obtain significant intercalation. The nanocomposite morphology was also probed using transmission electron microscopy, XRD, and positron annihilation lifetime spectroscopy. The bifunctional DGEBA resin gave better exfoliation than the resins of higher functionalities. This is attributed to better catalysis of the intragallery reaction by the organo-ions which reside within the galleries. Higher cure temperatures were also found to improve clay delamination and simultaneously increased toughness and modulus in case of the DGEBA- and TGAP-based materials. Free volume properties did not vary significantly between resins or with cur.
Sampling in the Smear Zone: Evaluation of Nondissolved Bias and Associated BTEX, MTBE, and TPH Concentrations in Ground Water Samples *

At fuel release sites, source zone characterization and monitoring for benzene, toluene, ethylbenzene and xylenes, methyl‐tert‐butyl‐ether, and total petroleum hydrocarbons as gasoline (TPHg) typically involve interpreting ground water data from grab (screening) samples and/or monitoring wells within the “smear zone,” where the soil pores contain both separate‐phase petroleum and dissolved‐phase constituents. Because the samples are collected within the smear zone, the ground water concentrations can be biased high by contributions from entrained nondissolved petroleum. The nondissolved bias is often not recognized by data users and can lead to erroneous interpretations and inputs for fate and transport modeling, mass flux calculations, risk assessments, etc., which can result in increased requirements for remediation or increased claims for damages in litigation. Ground water sample concentrations can be evaluated for potential bias by nondissolved petroleum using a phased approach that begins with comparison of the data to effective solubility concentrations for ethylbenzene, xylenes, and TPH derived from laboratory partitioning studies using fresh fuels. To reflect the reduction in effective solubility that results from weathering of the source, the ground water sample concentrations can also be compared to concentrations for samples that were collected with entrained sheen. In this data set of 47 gasoline release sites, the frequency of nondissolved bias in the reported ground water monitoring data ranged from 0.4% to 86%, depending on which concentration criterion was used as an indicator. If exceedances of the average concentration values for the laboratory partitioning and the sheen data are used, the frequency ranged from 9% to 20%. Also, reproducibility for duplicates collected from monitoring wells in the smear zone was unacceptable more than half of the time. This evaluation shows that a significant percentage of ground water monitoring data collected from the smear zone is unreliable for characterizing dissolved concentrations of petroleum constituents.
Deactivation of N2 (A3Σu+, v=0–7) by ground state nitrogen, ethane, and ethylene measured by kinetic absorption spectroscopy

Following the excitation of nitrogen and nitrogen/additive mixtures by single electron pulses the metastable nitrogen A3Σu+ is detected in its vibrational levels v=0–7 by absorption spectroscopy. The additives are ethylene, ethane, and NO. In pure nitrogen the prevailing process is a vibration‐vibration (V‐V) energy transfer process of the N2 A, v≥2 with Δv=2 to groundstate nitrogen. The rate constants increase with higher quantum numbers i.e., improving energy resonance up to a limiting collisional efficiency for this process of 10−2. The kinetic behavior of the vibrational states v=5, 6, 7 indicates strongly a collision induced intersystem crossing with the N2 B3Πg state. The rate constants for quenching of N2 A by ethane exhibit a strong increase with rising vibrational quantum number. Ethylene is generally more reactive and shows no strong dependence on the vibrational level. This is interpreted as a fast quenching of the electronic state by ethylene. While this latter process is relatively slow with .
Centrifuge Modeling of Cadmium Migration in Saturated and Unsaturated Soils

Researchers recently have come to recognize that geotechnical centrifuge can provide a powerful experimental tool for investigating the flow and transport of inorganic contaminants in soils. Inert, non-adsorptive inorganic compounds (e.g., sodium ions) rather than adsorptive heavy metals are often used as the chemical for the investigation of pollutant transport behavior in most centrifuge modeling. To overcome the shortcomings of this approach, centrifuge tests for the study of one-dimensional pollutant migration in both saturated and unsaturated soils were designed using an adsorptive pollutant (i.e., cadmium) and conducted at two centrifugal accelerations. In this study, the concentration profile of adsorptive cadmium along the depth of soil, the moisture content varying with the soil depth and the transport behavior of the cadmium in soils were investigated. The centrifuge results show that the cadmium concentration profiles are found to be similar for the centrifuge models performed at 15 g and 20 g and the one-dimensional moisture movement in the unsaturated soil can be reproducible. The validity of centrifuge modeling of adsorptive pollutants might be affected by the g-level that, in turn, determines the centrifuge testing time and affects the sorption equilibrium.
Hydrogen bonding and the static dielectric constant in liquid water

The static dielectric constants of several models for water are compared. These models have in common that they all give a good description of the energetics and structure of the hydrogen bonding in the liquid. Despite this similarity, the average molecular dipole moments vary over a range of 50% and the dielectric constants can differ by as much as a factor of 6. This observation verifies that the average dipole moment is a crucial parameter for the dielectric properties. On the other hand, this quantity seems of less importance for the stability of the hydrogen bonded network, which is largely determined by the details of the electrostatic and atom–atom interactions at short range. Applying this analysis we construct a polarizable model for liquid water with an average dipole moment of 2.6 D and a dielectric constant of 85. The structure and self‐diffusion coefficient are in good agreement with experiment, and the value of the dimer binding energy in the gas phase is also acceptable.
Land use and Water Quality in Guangzhou, China: A survey of ecological and Social Vulnerability in Four Urban Units of the Rapidly Developing Megacity

This interdisciplinary paper aims at Guangzhou’s development and its effects on surface andgroundwater quality taking the new city axis as an example. Qualitative morphological analyses, field mappings, interviews and water sampling of standard in-situ and various hydrochemical parameters were conducted between 2007 and 2009 in order to examine the following research questions: Which types of land use can be found within the new city axis? Are there infrastructure differences of water supply and wastewater disposal? How does land use affect the quality of surface and groundwater? How do inhabitants perceive and appraise settlement structures, infrastructures and environmental quality and how do they cope with their individual situation? Within four small-scale research areas, so-called urban units, different stages and types of development and factors influencing the water resources as well as spatial variations of water quality could be identified. Deficits in city planning, water supply and sanitation lead, for example, to informal building expansion and groundwater use as well as to high concentrations of coliform bacteria in urban rivers. A wide range of ecological and social vulnerabilities became obvious.
Phase transition anomaly observed in PbZrO3/Al2O3 nanocomposites

Effects of Al2O3 nanoparticle additions on the phase transitions of PbZrO3/Al2O3 nanocomposites were investigated. The nanocomposites were prepared by a solid-state reaction method. The phase transition behaviour of the composites was studied by dielectric measurements and differential scanning calorimetry. Nanoparticle additions produced a significant reduction in the temperature of the phase transition from ferroelectric to antiferroelectric phase during the cooling measurement. This resulted in a large thermal hysteresis. The results indicated that the intermediate ferroelectric phase of PbZrO3 is very sensitive to the Al2O3 impurity. It is proposed that changes in defect chemistry due to the reaction between the nanoparticles and the matrix during sintering are responsible for the anomaly in phase transition behaviour.
Dielectric Polarization in Polar Substances

A statistical mechanical theory of the static dielectric constant of polar substances is presented which differs from the previous theories of Kirkwood and Frohlich in that a precise evaluation of the distortion polarization term is made. The theory is applied to the dielectric constant of ordinary and heavy water and yields 2 percent agreement with experiment over the entire temperature range. Furthermore, the difference between the dielectric constant of water measured at visible and microwave frequencies can be ascribed to vibrations, such as the bending of the O–H–O bond. The calculated dielectric constant of ice agrees with experimental values within a mean deviation of 3 percent over a considerable temperature range using an approximate evaluation of the Pauling model for that substance. Various other liquids are also compared with experiment.
Soot Measurements in Steady and Pulsed Ethylene/Air Diffusion Flames Using Laser-Induced Incandescence

OF THE DISSERTATION SOOT MEASUREMENTS IN STEADY AND PULSED ETHYLENE/AIR DIFFUSION FLAMES USING LASER-INDUCED INCANDESCENCE by Hayri Serhat Sapmaz Florida International University, 2006 Miami, Florida Professor Norman D. H. Munroe, Major Professor Combustion-generated carbon black nano particles, or soot, have both positive and negative effects depending on the application. From a positive point of view, it is used as a reinforcing agent in tires, black pigment in inks, and surface coatings. From a negative point of view, it affects performance and durability of many combustion systems, it is a major contributor of global warming, and it is linked to respiratory illness and cancer. Laser-Induced Incandescence (LII) was used in this study to measure soot volume fractions in four steady and twenty-eight pulsed ethylene diffusion flames burning at atmospheric pressure. A laminar coflow diffusion burner combined with a very-highspeed solenoid valve and control circuit provided unsteady flows by forcing the fuel flow with frequencies between 10 Hz and 200 Hz. Periodic flame oscillations were captured by two-dimensional phase-locked LII images and broadband luminosity images for eight phases (0° – 360°) covering each period. A comparison between the steady and pulsed flames and the effect of the pulsation frequency on soot volume fraction in the flame
Effects of charge accumulation in a dielectric covered electrode system in air

The effect of space and surface charges on the increased insulation performance of a dielectric-covered electrode system in air during negative impulse voltage stress has been investigated. Results obtained from high-speed photographing, using a CCD camera, and the corresponding current measurements of the discharge phenomena in an air-insulated, dielectric-covered electrode system during negative lightning impulse voltage are presented. The correlation between the measured current pulses and the photographs of light events in the air-gap was found to be clear. Measurements revealed two different phenomena: at the front (voltage rise) of the impulse voltage, a negative discharge pulse emerged; while at the tail (voltage decay) of the impulse voltage, a sequence of small positive discharge pulses occurred. It is believed that discharges at the front cause heavy and distinct ionization in the air-gap which deposits charge, surface as well as space charges, at the covered electrode interfaces. The discharges at the tail correspond to re-distributions of the accumulated charge when the applied voltage vanishes. The discharges are mainly of the barrier discharge type.
Synthesis and Characterization of Nano- MnO2 for Electrochemical Supercapacitor Studies

Nanostructured MnO 2 was synthesized at ambient condition by reduction of potassium permanganate with aniline. Powder X-ray diffraction, thermal analysis (thermogravimetric and differential thermal analysis), Brunauer-Emmett-Teller surface area, and infrared spectroscopy studies were carried out for physical and chemical characterization. The as-prepared MnO 2 was amorphous and contained particles of 5-10 nm diameter. Upon annealing at temperatures >400°C, the amorphous MnO 2 attained crystalline α-phase with a concomitant change in morphology. A gradual conversion of nanoparticles to nanorods is evident from scanning electron microscopy and transmission electron microscopy (TEM) studies. High-resolution TEM images suggested that nanoparticles and nanorods grow in different crystallographic planes. Capacitance behavior was studied by cyclic voltammetry and galvanostatic charge-discharge cycling in a potential range from -0.2 to 1.0 V vs SCE in 0.1 M sodium sulfate solution. Specific capacitance of about 250 F g -1 was obtained at a current density of 0.5 mA cm -2 (0.8 A g -1 ).
ACCELERATED STORAGE TESTING OF FREEZE-DRIED IMMOBILIZED LACTOBACILLUS ACIDOPHILUS-FERMENTED BANANA MEDIA

Freeze-drying was applied as a drying method for the production of dehydrated immobilized Lactobacillus acidophilus-fermented banana medium containing high levels of probiotics and appropriate prebiotic (mainly fructooligosaccharides) contents in an attempt to develop dried synbiotic products. Ca-alginate and κ-carrageenan were used for the immobilization of L. acidophilus, and the immobilized bacteria were employed directly in the banana media fermentation. The fermented products were then freeze-dried. Results indicated that cell immobilization could provide effective protection to L. acidophilus, and reduce the damage caused by freezing and freeze-drying. Meanwhile, accelerated storage testing using temperatures of 50, 60 and 70C was applied to the dehydrated products. Gel-entrapped L. acidophilus appeared to have lower decimal reduction, and Ca-alginate immobilized cells had a better survival than κ-carrageenan. Results of accelerated storage test showed that immobilization could effectively increase the thermal resistance of entrapped microorganisms, and Ca-alginate showed a better effect than κ-carrageenan, and the beneficial effects increased with the decrease of the storage temperature. The freeze-dried products exhibited little hygroscopicity because of the consumption of monosaccharides during fermentation. Results revealed that freeze-drying could be used as a proper method for the development of dried product of immobilized L. acidophilus-fermented banana media, and accelerated storage test could be used to evaluate the storage stability of the dried products. PRACTICAL APPLICATIONS This research demonstrates the feasibility of the application of accelerated storage testing to the prediction of shelf life and storage stability of freeze-dried probiotic products manufactured by lactic acid bacteria fermentation. The Arrhenius equation was associated in this study. This will provide an efficient approach for the estimation of shelf life of probiotic products.
Composition and Biological Activity of Essential Oils from Lippia origanoides H.B.K.

Abstract Analyses of the leaf oils from three colletions of Lippia origanoides H.B. K. by GC/MS and 1H- and 13C-NMR showed a similar chemical composition. Carvacrol (33.5–42.9%) was identified as the major component together with γ-terpinene (8.0–10.5%), thymol (5.1–8.4%), methyl thymol (6.1–8.7%) and p-cymene (11.9–15.8%). In vitro evaluation of the oils showed significant antimicrobial activity against Escherichia coli, Staphylococus aureus, Staphylococus aureus MRSA, Candida albicans and Candida tropicalis.
Impact of sunlight/dark storage on natural spring water bottled in polyethylene terephthalate

The effect of two environmental variables, ultraviolet radiation and external air temperature, on polyethylene terephthalate (PET) bottled water was investigated over 100 days. The high pressure liquid chromatography results showed the migration of carbonyl compounds (acetaldehyde, formaldehyde and acetone) from PET bottles into water over 3 months. Storage of PET bottled water enhanced the process of carbonyl compounds migration especially under sunlight. The combination of these two environmental variables caused an increase of 15% in each carbonyl compound compared with storage in the dark at the laboratory. The maximum ambient Ultraviolet-B, Ultraviolet-A and Photo-synthetically Active Radiation intensity at the solar noon were 1.95, 23.0 W/m2 and 100,000 Lux, respectively.
Outdoor bronze statues: analysis of metal and surface samples

AbstractResults are presented from the analysis of 34 metal samples and 168 surface samples taken before conservation from cast bronze statues in 16 monuments in Ottawa, Canada. Metal samples, analyzed semi-quantitatively using standardless X-ray microanalysis, were predominantly copper with small amounts of tin, zinc and sometimes lead. Surface samples were analyzed by powder X-ray diffraction, X-ray energy spectrometry, Fourier transform infrared spectroscopy and/or gas chromatography-mass spectrometry. Of the 94 crystalline compounds identified in the surface samples, those detected most frequently were quartz, copper sulphate hydroxides (for example, brochantite, antlerite), copper chloride hydroxides (for example, atacamite, para tacamite), cuprite and gypsum. The main organic materials were a drying oil (probably linseed oil), poly(dimethyl siloxane) and waxes. The results presented here demonstrate the importance of two aspects of the conservation process: the need for proper surface cleaning to re.
Parameter-Free Prediction of DNA Conformations in Elongational Flow by Successive Fine Graining

Brownian dynamics simulations are used to predict the evolution of DNA conformations in elongational flow. The DNA molecule is represented by a bead-spring chain model, and excluded-volume and hydrodynamic interactions between the beads are taken into account. Two distinct types of behavior are examined, corresponding to infinite and finite chains. In the former case, Hookean springs are used, and simulations data accumulated for chains with increasing numbers of beads, N, are extrapolated to the limit N → ∞. In this nondraining limit, universal DNA stretch vs strain curves are obtained as a function of the solvent quality parameter z. In the case of finite chains with N k Kuhn steps, finitely extensible springs are used, and the extrapolation of finite chain data is restricted to the limit (N - 1) → N k . It is shown that in the presence of finitely extensible springs both the excluded-volume and hydrodynamic interaction parameters need to be redefined appropriately. The role of finite size effects and sensitivity to the choice of parameter values is examined by comparing the finite chain stretch vs strain curves with the universal curves. Theoretical predictions are also shown to compare favorably with experimental observations of DNA stretch.
On Monotonic Linear Interpolation of Neural Network Parameters

Linearly interpolating between initial neural network parameters and converged parameters after training with SGD typically leads to a monotonic decrease in the training objective. This Monotonic Linear Interpolation (MLI) property, ﬁrst observed by Goodfellow et al. [11], persists in spite of the non-convex objectives and highly non-linear training dynamics of neural networks. Extending on this work, we show that this property holds under varying network architectures, optimizers, and learning problems. We evaluate several possible hypotheses for this property that, to our knowledge, have not yet been explored. Additionally, we show that networks violating this property can be produced systematically, by forcing the weights to move far from initialization. The MLI property raises important questions about the loss landscape geometry of neural nets and highlights the need to further study its global properties.