Miracle-dz/UniFAR-FTUs huggingface dataset:
A Microfluidic Study Of Oil-waterSeparation Kinetics

We present the results of experiments studying droplet coalescence in a dense layer of emulsion droplets using microfluidic circuits. The microfluidic structure allows direct observation of shear-induced collisions and coalescence events between oil droplets dispersed in water. A mineral oil was chosen as the dispersed phase and a 9 wt% NaCl aqueous solution as the continuous phase. We determine the coalescence rate as a function of the droplet velocity and droplet concentration from image sequences measured with a high-speed camera. A trajectory analysis of colliding droplet pairs allows evaluation of the film drainage profile and coalescence time tc. From the coalescence times obtained for ten thousands of droplet pairs we calculate the coalescence time distributions for each set of experimental parameters, which are the mean droplet approach velocity 〈v0〉 and the mean dispersed phase fraction 〈φ〉. We discuss the potential of the procedure for the prediction of emulsion stability in industrial applications.
Transient Rheology of Wormlike Micelles

We report on the nonlinear shear rheology of wormlike micelles made of cetylpyridinium chloride (CP+,Cl-) and sodium salicylate (Na+,Sal-) diluted in 0.5 M NaCl-brine. A unique solution at concentration φ = 12% has been investigated (T = 20.3 °C). This strongly viscoelastic surfactant solution is an almost perfect Maxwellian fluid in the low-frequency range (ω < 100 rads-1). The stress relaxation function G(t) is decreasing monoexponentially as G(t) = G0 exp(−t/τR), where G0 (=240 Pa) is the elastic plateau modulus and τR (=1.0 s) the terminal relaxation time. The fundamental feature of the nonlinear rheology is the evidence of a constant and robust stress plateau (no hysteresis) above a characteristic strain rate labeled γI/N (γI/N = 0.9 ± 0.05 s-1). The solution at φ = 12% was selected because recent flow birefringence experiments revealed that the stress plateau mentioned previously is associated with a nonhomogeneous flow. Two phases of different birefringence and submitted to different velocity gra.
Peculiarities of nickel‐aluminium ferrites nanopowder structure

The ferrites powders of the compound NiAltFe2‐tO4 were produced up to technology of sol‐gel autocombustion. In accordance with x‐ray defractional analysis data the powder particles’ size is 18–33 nanometers. The magnetic and electronic ferrites structure was researched with the help of XANES and Mössbauer spectroscopy methods. The iron ions valency is equal + 3. Magnetic penetrability depends upon the content of nickel ions in the tetrahedral lattice points. The calculation shows that while increasing the nickel concentration in the tetrahedral lattice points the constant of magnetoelastic anisotropy is growing.
Two-way shape memory property and its structural origin of cross-linked poly(ε-caprolactone)

In this work, two-way shape memory (TWSM) properties and the corresponding structural origin of cross-linked poly(e-caprolactone) (cPCL) with different gel contents obtained by adopting different weight percentages of benzoyl peroxide (BPO) were investigated. The effects of gel contents on melting temperatures, crystallization temperatures and crystallinity of the cPCL materials were studied with differential scanning calorimetry. The TWSM properties of the samples were determined by dynamic mechanical analysis. It was found that gel content was the key factor determining the TWSM behavior, and higher gel content would result in the so-called robust TWSM effect for cPCL samples (cPCLx, x denoting the weight percentage of BPO). Compared with cPCL10, cPCL5 had larger elongation and lower recovery capabilities due to its lower gel content. However, the sample with much lower gel content (cPCL3) displayed almost no TWSM behavior, implying that an appropriate gel content was responsible for the TWSM characteristic. The crystalline structure of cPCLx subsequently changed when subjected to external stress. As the samples were cooled down under constant stress, higher stress would lead to a more oriented crystalline structure. Furthermore, concurrent wide-angle and small-angle X-ray scattering investigations revealed the structural evolution occurring during the TWSM process, indicating that the crystal orientation along the stretching direction took place simultaneously with the elongation during the cooling process.
Stimulated Brillouin Scattering of Higher-Order Acoustic Modes in Four-Core Tellurite Microstructured Optical Fiber

In this paper, we present a new way of enhancing the Stimulated Brillouin scattering (SBS) of higher-order acoustic modes in the four-core tellurite (TZLB) microstructured optical fiber (MOF). The Brillouin gain spectrum (BGS) in the MOF is calculated based on a full model analysis of the optical and acoustic properties. In contradict to the single-core tellurite MOF, BGS of the four-core tellurite MOF has three peaks, which are contributed by the fundamental and higher-order acoustic modes. The higher-order acoustic modes can enhance the interaction with the optical mode and provide a strong contribution to the Brillouin response.
Partitioning stoichiometric components of epilithic biofilm using mixing models

Epilithic biofilms are an important and complex food resource in shallow aquatic ecosystems. Standard methods of sampling these biofilms typically yield a combination of algal cells, other organic material, and inorganic sediment. Physical methods of isolating algal fractions rely on differences in density among biofilm components, and clean separation is not always possible. Here, we explore the application of linear mixing models to the problem of estimating nutrient content of biofilm components. This method is based on the assumption that variation in bulk sample elemental composition within a sampling site is due to differences among samples in relative composition. By using standard methods to quantify organic content and algal biomass within biofilm samples, the mixing model produces estimates of nutrient content of each end member. To test this method, we analyzed the phosphorus (P) content of algal cells, non‐algal organic material, and inorganic sediment associated with biofilm samples that increase in P‐content 4‐fold across a natural P gradient in lowland streams in Costa Rica. Our analyses show that nearly all of the observed increase in biofilm P from high‐P streams was due to elevated P‐content of algal cells, rather than P sorbed to inorganic sediments or in Prich heterotrophic bacteria. Results from the mixing model were supported by results from density fractionation. This linear mixing model approach complements empirical methods of separating complex food resources and may lead to a better understanding of trophic interactions in aquatic food webs.
Two Symmetrically Bis‐substituted Pyrene Derivatives: Synthesis, Photoluminescence, and Electroluminescence

Two kinds of cyanophenyl terminated pyrene derivatives for organic light-emitting diodes were synthesized and characterized by UV/Vis, fluorescence (FL), 1H NMR, MALDI-TOF, CV and TGA. Both compounds exhibited blue photoluminescence and high fluorescent quantum yield of 85% and 75% in solutions. Due to the presence of acetylene spacer, the compound distinguishes itself by high coplanarity, high thermal stability, little Stokes' shift and clear excimer formation in the solid state from the acetylene-free compound. In order to suppress the molecular aggregation, the electroluminescent properties were studied by doing the materials in PVK. The result proved that energy transfer happened from the host PVK to the materials.
Maintenance strategies for on-site water disinfection by ultraviolet lamps on dairy farms

Bacteria have been detected in many water supplies on dairy farms, and the water used to wash milking equipment should be free of bacteria. This study evaluated two ultraviolet (UV) technologies, with and without automatic sleeve cleaning device, as on-farm water disinfection system. No fouling was observed during 6 months of continuous operation of the self-cleaning UV system. The dose provided by a non self-cleaning UV lamp decreased by 41% and 96% after 30 and 60 days of continuous operation, respectively, at the maximum recommended water hardness and iron levels. However, when the lamp was operated 2 hours, twice daily, as on dairy farms disinfecting water solely to wash milking equipment, the dose decreased by 9% and 50% after 30 and 60 days, respectively. A UV system with self-cleaning capability is thus recommended for most farms, or monthly manual cleanings will be required to limit fouling and ensure water disinfection. Both UV technologies were efficient in disinfecting water containing high pathogen concentrations. A dose of
STUDIES ON THE ADSORPTION OF FURFURAL FROM AQUEOUS SOLUTION ONTO LOW-COST BAGASSE FLY ASH

The present study deals with the sorptive removal of furfural from aqueous solution by carbon-rich bagasse fly ash (BFA). Batch studies were performed to evaluate the influence of various experimental parameters, namely, initial pH (p H 0), adsorbent dose, contact time, initial concentration, and temperature on the removal of furfural. Optimum conditions for furfural removal were found to be p H 0 ≈ 5.5, adsorbent dose ≈4 g/L of solution, and equilibrium time ≈4 h. The adsorption followed pseudo-second-order kinetics. The effective diffusion coefficient of furfural is of the order of 10−13 m2/s. Equilibrium adsorption data on BFA was analyzed by Freundlich, Langmuir, Dubnin-Radushkevich, Redlich-Peterson, and Temkin isotherm equations using regression and error analysis. The Redlich-Peterson isotherm was found to best represent the data for furfural adsorption onto BFA. Adsorption of furfural on BFA is favorably influenced by a decrease in the temperature of the operation. Values of the change in entropy (ΔS 0) and heat of adsorption (ΔH 0) for furfural adsorption on BFA were negative. The high negative value of change in Gibbs free energy (ΔG 0) indicates the feasible and spontaneous adsorption of furfural on BFA.
CUBIC ANTIMONIC ACID AS COLUMN-PACKING MATERIAL FOR CHROMATOGRAPHIC LITHIUM ISOTOPE SEPARATION

The applicability of granular cubic antimonic acid (C-SbA) as column packing material in chromatographic lithium isotope separation was investigated. The feed solution should have the buffer capacity to promote lithium uptake, and its pH has to be kept as low as 2.25 to prevent the decomposition of the granular C-SbA in order to obtain a sharp front boundary of the lithium sorption zone. The pH and the chemical composition of the eluent should be finely controlled to obtain a displacement-type chromatogram. The lithium isotope separation effect was about ten times larger than that achieved on an organic ion exchanger.
A Molecular Dynamics Study of Tryptophan in Water

Molecular dynamics simulations of a single tryptophan amino acid in water were performed with the CHARMM molecular mechanics program using the modified TIP3P, the refined SPC, and the original SPC/E water models. All these empirical water models are similar in nature, but small differences give significant differences in their properties for liquid water. Nanosecond molecular dynamics simulations were carried out in the NVT, NVE, or NPT ensembles using a cubic simulation cell furnished with periodic boundary conditions. The calculations of long-range interactions were performed with two different methods, the atom-based spherical cutoff method with force shifting, where the nonbonded interactions were smoothly shifted to zero at the cutoff distance, and the particle-mesh Ewald technique. Transition dipole autocorrelation functions and reorientation times of tryptophan were calculated and compared to experimental values. Tryptophan hydration was affected by the water model and the treatment of long-range electrostatic interactions. The reorientation time of tryptophan depended strongly on the water model used, and the viscosity of the model liquid was found to correlate with the tryptophan translational and rotational dynamics in water. Statistical accuracy and errors in the analyses are discussed.
Tunneling and dispersion in 3D phononic crystals

Abstract Tunneling and dispersion of ultrasonic pulses is investigated in 3D phononic crystals consisting of 0.8 mm-diameter tungsten carbide beads that are close packed in a fcc crystal array embedded in either water or epoxy. Pulsed ultrasonic techniques allow us to measure the phase velocity and group velocity, i.e. the dynamics of wave propagation, as well as the transmission coefficient. Our experimental data are well interpreted using multiple scattering theory (MST). In the tungsten carbide/water crystals, dispersion phenomena were studied at frequencies in and around the gap in the ΓL direction. A strong suppression of the group velocity, and large variations of the group velocity dispersion (GVD) were found at frequencies around the band edges. By contrast, fast group velocities and nearly constant GVD with values around zero were observed at gap frequencies, indicating that tunneling in phononic crystals is essentially dispersionless. In the tungsten carbide/epoxy crystals a wide gap (to our knowledge, largest measured 3D band gap) was measured covering a frequency range from 1.2 MHz to 4.3 MHz along the ΓL crystal direction. The agreement between the theory and experiments gives strong evidence of the existence of a large complete gap (1.5 MHz to 3.9 MHz), which is theoretically predicted from the band structure calculations.
Incentive Based Demand Response Program for Power System Flexibility Enhancement

This article proposes a DR program characterized by a novel compensation scheme. The proposed scheme recognizes the different characteristics of curtailment, such as the total length of curtailments within a window of time, or the number of separate curtailment events (i.e., curtailment startup), and compensates the end-user accordingly. The proposed compensation scheme features a piece-wise reward function comprised of two intervals. DR participants receive a onetime reward upfront when they enroll in the DR program and accept a set of predefined curtailment aspects. Curtailment aspects in excess of the agreed quantities are rewarded at a linear rate. This design is tailored to appeal to residential DR participants, and aims to secure sufficient flexibility at minimum cost. The parameters of the smart contract are optimized such that the system’s social welfare is maximized. The optimization problem is modeled as a mixed-integer linear program. Consequently, this article updates the unit-commitment (UC) formulation with the commitment aspects of DR units. The proposed extension to the UC problem considers the critical aspects of DR participation, such as: the total length of interruptions within a window, the frequency of interruptions within a time-window irrespective of their length, and the net energy deviation from the original load profile. Deployment of the smart DR contract in the unit dispatch problem requires translating DR participants’ characteristics to their equivalent aspects in conventional thermal generators, such as minimum up time, minimum down-time, start-up and shutdown costs. The obtained results demonstrate significant improvement in social welfare, notable reduction of curtailed renewable energy and reduction in extreme ramping events of conventional generators.
Adsorption on Edge-Functionalized Bilayer Graphene Nanoribbons: Assessing the Role of Functional Groups in Methane Uptake

A combination of ab initio and classical Monte Carlo simulations is used to investigate the effects of functional groups on methane binding. Using Moller-Plesset (MP2) calculations, we obtain the binding energies for benzene functionalized with NH2, OH, CH3, COOH, and H2PO3 and identify the methane binding sites. In all cases, the preferred binding sites are located above the benzene plane in the vicinity of the benzene carbon atom attached to the functional group. Functional groups enhance methane binding relative to benzene (-6.39 kJ/mol), with the largest enhancement observed for H2PO3 (-8.37 kJ/mol) followed by COOH and CH3 (-7.77 kJ/mol). Adsorption isotherms are obtained for edge-functionalized bilayer graphene nanoribbons using grand canonical Monte Carlo simulations with a five-site methane model. Adsorbed excess and heats of adsorption for pressures up to 40 bar and 298 K are obtained with functional group concentrations ranging from 3.125 to 6.25 mol 96 for graphene edges functionalized with OH, NH2, and COOH. The functional groups are found to act as preferred adsorption sites, and in the case of COOH the local methane density in the vicinity of the functional group is found to exceed that of bare graphene. The largest enhancement of 44.5% in the methane excess adsorbed is observed for COOH-functionalized nanoribbons when compared to H terminated ribbons. The corresponding enhancements for OH- and NH2-functionalized ribbons are 10.5% and 3.7%, respectively. The excess adsorption across functional groups reflects the trends observed in the binding energies from MP2 calculations. Our study reveals that specific site functionalization can have a significant effect on the local adsorption characteristics and can be used as a design strategy to tailor materials with enhanced methane storage capacity.
Tumor inhibitors. 126. New cytotoxic neolignans from Aniba megaphylla Mez

The isolation and elucidation of the structure and stereochemistry of megaphone ( l ) , a new cytotoxic neolignan from Aniba rnegaphylla Mez. , are reported. Chemical and spectral evidence supported structure 1 for megaphone, and a direct x-ray crystallographic analysis confirmed the structure and established the stereochemistry. Two additional new cytotoxic neolignans, megaphone acetate (2) and megaphyllone acetate (3), were isolated and their structures deduced in light of the structure of 1. The lack of activity of these neolignans as inhibitors of mitosis in sea urchin eggs is discussed in terms of structural features.
Differential cross sections for ionization of methane, ammonia, and water vapor by high velocity ions

Cross sections, differential in the energy of secondary electrons, for ionization of methane, ammonia, and water vapor by high energy protons are presented. The results are based on a model that uses photoabsorption and ion impact ionization data to evaluate the coefficients in Bethe’s asymptotic cross section for inelastic scattering of high velocity ions. Model cross sections are compared with previously published data and new data on ionization of methane and water vapor by 3.0 and 4.2 MeV protons. The simple, analytic model should be very useful in transport calculations where differential ionization cross sections over a broad range of primary and secondary energies are needed.
Kelvin Notation for Stabilizing Elastic-Constant Inversion

Inverting a set of core-sample traveltime measurements for a complete set of 21 elastic constants is a difficult problem. If the 21 elastic constants are directly used as the inversion parameters, a few bad measurements or an unfortunate starting guess may result in the inversion converging to a physically impossible solution . Even given perfect data, multiple solutions may exist that predict the observed traveltimes equally well. We desire the inversion algorithm to converge not just to a physically possible solution, but to the best(i. e. most physically likely) solution of all those allowed. We present a new parameterization that attempts to solve these difficulties. The search space is limited to physically realizable media by making use of the Kelvin eigenstiffness-eigentensor representation of the 6 x 6 elastic stiffness matrix. Instead of 21 stiffnesses, there are 6 eigenstiffness parametersand 15 rotational parameters . The rotational parameters are defined using a Lie-algebra representation that avoids the artificial degeneracies and coordinate-system bias that can occur with standard polar representations. For any choice of these 21 real parameters, the corresponding stiffness matrix is guaranteed to be physically realizable. Furthermore, all physically realizable matrices can be represented in this way. This new parameterization still leaves considerable latitude as to which linear combinations of the Kelvin parameters to use, and how they should be ordered. We demonstrate that by careful choice and ordering of the parameters, the inversion can be relaxedfrom higher to lower symmetry simply by adding a few more parameters at a time. By starting from isotropy and relaxing to the general result in stages (isotropy, transverse isotropy, orthorhombic, general), we expect that the method should find the solution that is closest to isotropy of all those that fit the data.
Land-use and land-cover change and its environmental implications in a tropical highland watershed, Ethiopia

This study analysed long-term land-use and land-cover change (LUCC) in a highland watershed covering an area of about 154 km2 in the Blue Nile basin of Ethiopia. Two sets of panchromatic aerial photographs (1957 and 1982) and a Landsat TM image (2001) were the main input data from which three land-use and land-cover maps were produced by employing geographical information systems/remote sensing techniques. These data were complemented by some socio-economic data that were generated by using household survey, key-informant interview and group discussion methods. The results show that in regard to land-use and land-cover, the major change has been the reduction of areas under natural vegetation cover and expansion of open grassland, cultivated areas and settlements. Over the four and a half decades considered, areas of forest and dense tree cover and shrub grassland decreased by 64 and 6%, respectively. Forest and dense tree cover experienced the greatest change; from accounting for ∼9% of the total area of the watershed in 1957 to only ∼3% in 2001. In general, much of the de-vegetation occurred between 1982 and 2001. Cropland and rural settlement showed a small but consistent increase between 1957 and 2001. Riparian vegetation decreased during the first period, but increased almost to the same level during the second period by gaining land from the other land-use and land-cover types. The observed LUCCs were driven by a combination of proximate and underlying causes. These include increasing demographic pressure and associated demands on environmental resources, widespread rural poverty and inadequate management of common property resources owing to poorly defined ownership arrangements. There is a need for short-term and long-term strategies to ensure sustainable land management and agricultural development in the watershed.