Miracle-dz/UniFAR-FTUs huggingface dataset:
Energy consumption of tree shakers as a function of frequency

In the last decade considerable progress was achieved in the theory of tree shakers used for fruit harvesting. New calculation methods were developed including the vibrating soil mass which enabled the calculation of effective soil masses on a strictly physical basis. However, these earlier investigations did not treat with the effect of stroke frequency. In these investigations, first of all, the friction behavior of the soil mass is discussed as a function of stroke frequency. It turned out that the decrease and shifting of the soil deformation waves as a function of distance measured from the tree trunk are the main sources of an intensive friction between the neighbouring soil layers. As a consequence, the logarithmic decrement (and not the damping coefficient) of the soil will be more or less constant as a function of stroke frequency, at least in the investigated frequency range. At lower attachment heights the soil friction losses dominate independently on stroke frequency. The virtual spring constant of the soil body is also frequency dependent. Due to the presence of combined frictional and viscous losses, the energy method seems to be the best one to analyze the effect of stroke frequency on the various operational parameters.
Energy Band Alignment between Anatase and Rutile TiO2

Using photoelectron spectroscopy, the interface formation of anatase and rutile TiO2 with RuO2 and tin-doped indium oxide (ITO) is studied. It is consistently found that the valence band maximum of rutile is 0.7 ± 0.1 eV above that of anatase. The alignment is confirmed by electronic structure calculations, which further show that the alignment is related to the splitting of the energy bands formed by the O 2pz lone-pair orbitals. The alignment can explain the different electron concentrations in doped anatase and rutile and the enhanced photocatalytic activity of mixed phase particles.
Cadmium application and pH effects on growth and cadmium accumulation in switchgrass

Recent efforts have been initiated to develop switchgrass (Panicum virgatum L.), which requires nitrogen (N) for productivity, as a bioenergy crop. Alternatives to inorganic fertilizers are needed to reduce input costs and maintain a positive energy balance. Municipal sludge may be an economical source of N and other nutrients for biomass production but switchgrass's response to heavy metals in the sludge is unknown. A study was conducted to determine the interaction of soil pH and Cd application on biomass accumulation and Cd allocation of switchgrass. ‘Alamo’ switchgrass was grown in pots at five soil pH levels (4.0, 5.1, 5.8, 6.6, and 7.3) and four soil Cd levels (0, 50, 100, and 200 mg Cd kg−1). Two hundred milligrams Cd kg−1 decreased biomass accumulation of all plant components by 95%. Cadmium concentrations of 900 mg kg−1 were found in root tissue of plants grown in soil with 200 mg Cd kg−1 and a pH of 4.0. Soil pH should be maintained near neutral to minimize Cd accumulation by switchgrass. †Research conducted while employed by Texas A&M University Agricultural Research and Extenstion Center, Route 2, Box 10888, Stephenville, TX 76401.
Hyphenated Techniques in Liquid Chromatography as Current Trends in Natural Products Analysis

Historically, drug discovery from natural products has been a time and resource - intensive process. Bioassay - guided isolation of natural products often leads to already known compounds of limited, or no chemica l or pharmacological interest. Some bioactive compounds are unstable and separation using the traditional approach is often difficult. Full structural elucidation of pure compounds usually requires milligram quantities of compounds and that may require ext racting large kilogram quantities of material especially for minor compounds. Rapid detection of biologically active natural products is desired, and to achieve this, dereplication of crude extracts performed prior to isolation work is of crucial importanc e for avoiding the isolation of a known constituent. Natural products research, as a strategy in drug discovery, has evolved over the last two decades with technological advances in the tools which are prerequisite in isolation and structural elucidation o f compounds. Such is the shift from the classical/traditional stand - alone instrumental analytical approaches to newer hyphenated techniques (LC - UV/DAD, LC - MS and LC - NMR). This review describes the general principles and literature applications of these prod uctivity tools in natural products isolation and structural elucidation and also as assay tools for quality control studies, with a discussion on their successes
Estimation of Water Solubility of Polycyclic Aromatic Hydrocarbons Using Quantum Chemical Descriptors and Partial Least Squares

Quantitative Structure-Property Relationship (QSPR) modeling is a powerful approach for predicting the properties of environmental organic pollutants from their structure descriptors. In this study, QSPR models were established for estimating the water solubility of Polycyclic Aromatic Hydrocarbons (PAHs). Quantum chemical descriptors computed with density functional theory at the B3LYP/6-31G(d) level and Partial Least Squares (PLS) analysis with an optimizing procedure were used to generate QSPR models for the logarithm of the water solubility of PAHs. Two optimized models with high correlation coefficients (R2=0.966 and 0.970) were obtained for estimating logarithmic mass and molar concentration of water solubility, respectively. The internal statistics results of a cross-validation test (=0.928 and 0.937, respectively) showed both the models had high precision and good prediction capability. The logarithmic water solubility values predicted by the models are close to those observed. The PLS analysis indicated that PAHs with larger electronic spatial extent and lower total energy values tend to be less soluble.
Density Functional Theory (DFT) Study of the Hydration Steps of Na+/Mg2+/Ca2+/Sr2+/Ba2+-Exchanged MontmorillonitesChromatography

Theoretical models of the mechanical properties of hydrated smectites, saturated with a variety of cations, are of much value in determining the potential for their use in various applications, including clay-polymer nanocomposites, but the development of such models is still in its infancy. The purpose of this study was to calculate the effects of divalent cations on the structural and mechanical elasticity of montmorillonite under different degrees of hydration. A theoretical study of the swelling and hydration behavior of montmorillonite was, therefore, undertaken using density functional theory (DFT) to investigate the basal spacing behavior of the homoionic montmorillonite with varying amounts of water in the interlayer space. The effect of the degree of the hydration of divalent interlayer cations (Mg2+/Ca2+/ Sr2+/Ba2+) on the structure expansion of the interlayer space was analyzed. In addition, the results obtained were compared to calculations performed on the montmorillonite model with a monovalent cation (Na+). The basal spacing (d001) is governed by the size and the degree of hydration of the countercations. The structures containing divalent cations are more compact than structures with monovalent cations. Ba-exchanged montmorillonite was found to have the largest d001 value for any degree of hydration (‘dry,’ one water layer, or two layers). The basal spacings of ‘dry’ montmorillonite exchanged with small cations, Mg2+ and Ca2+, are very similar. In hydrated models, the d001 expansion correlates with the ionic radius of the interlayer cation. The dependence of the total electronic energy on the volume expansion was calculated. From the energetic curves, bulk modulus (B0) was obtained by fitting in order to show how the compliance of the material depends on the type of interlayer cation and on the degree of hydration. With increasing water content in the interlayer space, the bulk modulus decreased, suggesting that the c-axial compression becomes easier with increasing hydration of the clay mineral. The values of the bulk modulus in hydrated systems are less sensitive to the type of the interlayer cation.
Finding New Diagnostic Information for Detecting Glaucoma using Neural Networks

We describe a new approach to automated Glaucoma detection in 3D Spectral Domain Optical Coherence Tomography (OCT) optic nerve scans. First, we gathered a unique and diverse multi-ethnic dataset of OCT scans consisting of glaucoma and non-glaucomatous cases obtained from four tertiary care eye hospitals located in four different countries. Using this longitudinal data, we achieved state-of-the-art results for automatically detecting Glaucoma from a single raw OCT using a 3D Deep Learning system. These results are close to human doctors in a variety of settings across heterogeneous datasets and scanning environments. To verify correctness and interpretability of the automated categorization, we used saliency maps to find areas of focus for the model. Matching human doctor behavior, the model predictions indeed correlated with the conventional diagnostic parameters in the OCT printouts, such as the retinal nerve fiber layer. We further used our model to find new areas in the 3D data that are presently not being identified as a diagnostic parameter to detect glaucoma by human doctors. Namely, we found that the Lamina Cribrosa (LC) region can be a valuable source of helpful diagnostic information previously unavailable to doctors during routine clinical care because it lacks a quantitative printout. Our model provides such volumetric quantification of this region. We found that even when a majority of the RNFL is removed, the LC region can distinguish glaucoma. This is clinically relevant in high myopes, when the RNFL is already reduced, and thus the LC region may help differentiate glaucoma in this confounding situation. We further generalize this approach to create a new algorithm called DiagFind that provides a recipe for finding new diagnostic information in medical imagery that may have been previously unusable by doctors.
Structural transition of post-spinel phases CaMn2O4, CaFe2O4, and CaTi2O4 under high pressures up to 80 GPa

Abstract Three structures of CaMn2O4, CaFe2O4, and CaTi2O4 have been proposed as post-spinel phases. Because these structures are very similar, several ambiguities and inconsistencies appear in high-pressure studies, leading to many problems that are yet to be solved. Systematic powder diffraction studies related to these three phases were conducted under high pressure using synchrotron radiation. All three samples have further high-pressure polymorphs. CaMn2O4 transforms to the CaTi2O4-type structure at about 30 GPa. The MnO6 octahedron in the lower-pressure structure is distorted by the Jahn-Teller effect. A new phase was observed at pressures above 50 GPa during compression of CaFe2O4. Rietveld profile fitting analysis of diffraction data at 63.3 GPa demonstrated that the high-pressure structure, with space group Pnam, is produced via a martensitic transformation by displacing atoms in every third layer perpendicular to the c axis. CaTi2O4 also has a new high-pressure polymorph above 39 GPa with space group Bbmm. The most probable post-spinel candidate in the mantle is the CaTi2O4-type structure. The CaMn2O4-type structure is only formed at high pressure from spinel phases with atoms susceptible to Jahn-Teller distortion.
Ternary Phase Behavior of Milk Fat Fractions

Milk fat was sequentially crystallized from ethyl acetate into three major componentsa high melting fraction (HMF), a middle melting fraction (MMF), and a low melting fraction (LMF)in 12%, 34%, and 54% (w/w) yields, respectively. The phase behavior of mixtures of HMF, MMF, and LMF was studied using solid fat content vs temperature data. Binary and ternary phase diagrams of mixtures of the three components were constructed. Binary HMF−MMF mixtures displayed monotectic solution behavior, forming a solid solution, whereas both LMF−HMF and LMF− MMF binaries formed partial solid solutions. The LMF fraction interacted more strongly with MMF than with HMF. Ternary phase diagrams showed the complex interaction between the three components simultaneously. On average, monotectic solution behavior was observed in mixtures of the three fractions at temperatures between 0 and 15 °C and above 30 °C. A eutectic was observed between a MMF−HMF solid solution and LMF at 0 °C. At temperatures corresponding to the melting ra.
Review on Cyanogenic Bacteria for Gold Recovery from E-Waste

Electronic waste (E-waste) is recognized as a new emerging and fast-growing waste stream, and may be considered as a secondary ore for the recovery of some precious metals (such as gold). A number of control technologies have been conducted for gold recovery, and in which, cyanidation is widely used. In recent years, an alternate approach to the gold cyanidation process is being considered, in which the aim is to replace with the microorganism, specifically cyanogenic bacteria such as Chromobacterium violaceum, Pseudomonas fluorescens, Pseudomonas aeruginosa and Escherichia coli. All these species can produce cyanide ions and dissolve gold in their metabolic processes. The mechanism is a combination of chemical knowledge (interaction of metals and cyanide) with microbiological principles (biological cyanide formation) regarding metal solubilization from waste printed circuit boards and the formation of water-soluble cyanide complexes. And the activity of cyanogenic bacteria is affected by many factors, such as pH, dissolved oxygen pulp density and nutriment, especially several metal ions, which can serve as the catalyst in the metabolism. Now researchers are devoting themselves to looking for the proper conditions, not only from the bacteria themselves, but also the combination of many methods, which can reinforce the cyanide generation and improve gold leaching efficiency. At present the reported leaching efficiency of gold with cyanogenic is approximately 70%. As the continuous optimization of conditions, the industrial application can be expected soon.
EXTRACTION RATES OF OIL FROM TOMATO SEEDS WITH SUPERCRITICAL CARBON DIOXIDE

Tomato seed oil was extracted with supercritical carbon dioxide in a semibatch-flow extraction apparatus. The effect of milling of seeds and solvent flow rate on the extraction behavior was studied. The extraction rate increased as solvent flow rate increased. Milling the seeds prior to extraction enhanced the extraction rate. During extraction from milled seeds, the solute from the cells opened by milling was extracted fast, and the solute inside the cell walls was extracted slowly. Mathematical models based on two distinct extraction periods with different extraction rate were applied to analyze the experimental data. The models simulated the extraction behavior satisfactorily.
Rheological Characteristics of Carob Pekmez

This study investigated the physicochemical properties and rheological behavior of carob pekmez. Rheological measurements were undertaken at 30, 40, 50, 60, and 70°C using a rotational viscometer at the shear rate of 5, 10, 20, 50, and 100 1/s. The flow characteristics of carob pekmez were described by the power law and Herschel-Bulkley models. The Herschel-Bulkley model was found to be the best to describe the rheological property with the coefficient of determination higher than 0.998. Carob pekmez exhibited a time-independent shear thickening behavior. An Arrhenius equation was used to describe the effect of temperature on viscosity and Ea value of the carob pekmez was calculated as 103.86 kJ mol−1.
Microbially Induced Calcium Carbonate Precipitation on Surface or in the Bulk of Soil

Microbial precipitation of calcium carbonate takes place in nature by different mechanisms. One of them is microbially induced carbonate precipitation (MICP), which is performed due to bacterial hydrolysis of urea in soil in the presence of calcium ions. The MICP process can be adopted to reduce the permeability and/or increase the shear strength of soil. In this paper, a study on the use of Bacillus sp. , which was isolated from tropical beach sand, to perform MICP either on the surface or in the bulk of sand is presented. If the level of calcium salt solution was below the sand surface, MICP took place in the bulk of sand. On the other hand, if the level of calcium salt solution was above the sand surface, MICP was performed on the sand surface and formed a thin layer of crust of calcium carbonate. After six sequential batch treatments with suspension of urease-producing bacteria and solutions of urea and calcium salt, the permeability of sand was reduced to 14 mm/day (or 1.6×10−7 m/s) in both cases of bulk and surface MICP. Quantities of precipitated calcium after six treatments were 0.15 and 0.60 g of Ca per cm2 of treated sand surface for the cases of bulk or surface MICP, respectively. The stiffness of the MICP treated sand also increased considerably. The modulus of rupture of the thin layer of crust was 35.9 MPa which is comparable with limestone.
Thermodynamic, kinetic, and equilibrium studies on phenol removal by use of cashew nut shell

Adsorption of phenol from aqueous solution onto cashew nut shell (CNS) was investigated to assess the possible use of this adsorbent. The influence of various parameters such as contact time, phenol concentration, adsorbent dose, pH, and temperature has been studied. Studies showed that the pH of aqueous solutions affected phenol removal as a result of decrease in removal efficiency with increasing solution pH. The experimental data were analysed by the Langmuir equation. Equilibrium data fitted well with the Langmuir model with maximum monolayer adsorption capacity of 5.405 mg/g. Thermodynamic parameters such as ΔG°, ΔH°, and ΔS° have also been evaluated and it has been found that the sorption process was feasible, spontaneous, and exothermic in nature. The pseudo-first-order and pseudo-second-order kinetic models were selected to follow the adsorption process. Kinetic parameters, rate constants, equilibrium sorption capacities and related correlation coefficients, for each kinetic model were calculated and discussed. It was shown that the adsorption of phenol could be described by the pseudo-second-order equation, suggesting that the adsorption process is presumable a chemisorption. The CNS investigated in this study showed good application potential for the removal of phenol from aqueous solution. L'adsorption du phenol d'une solution aqueuse sur une coque de noix de cajou (CNC) a ete analysee pour evaluer l'utilisation possible de cet adsorbant. L'influence de divers parametres comme le temps de contact, la concentration de phenol, la dose d'adsorbant, le pH et la temperature a ete etudiee. Des etudes ont demontre que le pH des solutions aqueuses avait un effet sur le retrait du phenol comme resultat de la diminution de l'efficacite de retrait avec un pH de solution croissant. Les donnees experimentales ont ete analysees par l'equation de Langmuir. Les donnees d'equilibre correspondaient bien au modele de Langmuir avec une capacite d'adsorption monocouche maximale de 5.405 mg/g. Des parametres thermodynamiques comme ΔG°, ΔH° et ΔS° ont egalement ete evalues et on a decouvert que le processus de sorption etait faisable, spontane et de nature exothermique. Les modeles cinetiques de pseudo premier ordre et pseudo second ordre ont ete choisis pour suivre le processus d'adsorption. Les parametres cinetiques, constantes de vitesse, capacites de sorption d'equilibre et cœfficients de correlation connexes pour chaque modele cinetique ont ete calcules et discutes. On a decouvert que l'on peut decrire l'adsorption de phenol par l'equation de pseudo second ordre, suggerant que le processus d'adsorption est sans doute une chimisorption. La CNC analysee dans cette etude demontrait un bon potentiel d'application pour le retrait du phenol d'une solution aqueuse.
Photon absorption and photocurrent in solar cells below semiconductor bandgap due to electron photoemission from plasmonic nanoantennas

We model the electron photoemission from metal nanoparticles into a semiconductor in a Schottky diode with a conductive oxide electrode hosting the nanoparticles. We show that plasmonic effects in the nanoparticles lead to a substantial enhancement in photoemission compared with devices with continuous metal films. Optimally designed metal nanoparticles can provide an effective mechanism for the photon absorption in the infrared range below the semiconductor bandgap, resulting in the generation of a photocurrent in addition to the photocurrent from band‐to‐band absorption in a semiconductor. Such structure can form the dais of the development of plasmonic photoemission enhanced solar cells. Copyright © 2012 John Wiley & Sons, Ltd.
Volcanic Ash‐Induced Decomposition of EB‐PVD Gd2Zr2O7 Thermal Barrier Coatings to Gd‐Oxyapatite, Zircon, and Gd, Fe‐Zirconolite

The resistance of EB-PVD Gd2Zr2O7 thermal barrier coatings against high-temperature infiltration and subsequent degradation by molten volcanic ash is investigated by microstructural analysis. At 1200°C, EB-PVD Gd2Zr2O7 coatings with silica rich, artificial volcanic ash (AVA) overlay show a highly dynamic and complex recession scenario. Gd2O3 is leached out from Gd2Zr2O7 by AVA and rapidly crystallizes as an oxyapatite-type solid-solution (Ca,Gd)2(Gd,Zr)8(Si,Al)6O26. The second product of Gd2Zr2O7 decomposition is Gd2O3 fully stabilized ZrO2 (Gd-FSZ). Both reaction products are forming an interpenetrating network filling open coating porosity. However, first-generation Gd-oxyapatite and Gd-FSZ are exhibiting chemical evolution in the long term. The chemical composition of Gd-oxyapatite does evolve from Ca,Zr enriched to Gd-rich. AVA continuously leaches out Gd2O3 from Gd-FSZ followed by destabilization to the monoclinic ZrO2 polymorph. Finally, zircon (ZrSiO4) is formed. In addition to the prevalent formation of Gd-oxyapatite, a Gd-, Zr-, Fe-, and Ti-rich oxide is observed. From chemical analysis and electron diffraction it is concluded that this phase belongs to the zirconolite-type family (zirconolite CaZrTi2O7), exhibiting an almost full substitution Ca2+ + Ti4+ Gd3+ + Fe3+. As all Gd2Zr2O7 decomposition products with the exception of ZrSiO4 exhibit considerable solid solubility ranges, it is difficult to conclusively assess the resistance of EB-PVD Gd2Zr2O7 coatings versus volcanic ash attack.
Waterborne oil-modified polyurethane coatings via hybrid miniemulsion polymerization

As part of a wider effort to develop a new class of waterborne coatings, hybrid miniemulsion polymerization was carried out with acrylic monomers (methyl methacrylate, butyl acrylate, and acrylic acid) in the presence of oil-modified polyurethane resin. Latexes with different ratios of resin to acrylic monomers were synthesized. The monomer emulsions prepared for hybrid miniemulsion polymerization showed excellent shelf-life stability (>5 months) and the polymerization was run free of coagulation. Solvent extraction indicated that the grafting efficiency of polyacrylics was greater than 29% for all the samples produced. A 13C solution NMR spectrum showed that a substantial fraction of the original carbon double bonds (>61%) in oil-modified polyurethane remained after polymerization for film curing. Films obtained from the latexes presented good adhesion properties and fair hardness properties. © 2000 John Wiley & Sons, Inc. J Appl Polym Sci 76: 105–114, 2000