Miracle-dz/UniFAR-FTUs huggingface dataset:
On the mechanism of self-deceleration of the thin oxide film growth

The objective of this work was to investigate the kinetics of the two-phase oxide film growth on the α-Fe surface at temperatures of 650–750 K. We experimentally determined that the film thickness (h)–time oxidation (τ) relationship in the range denoted above is a logarithmic function, whereas Cabrera and Mott’s theory gives a square law of film growth. In our work, analytical treatment of experimental data was made based on this theory, but we propose that self-deceleration of the film growth is caused not by attenuation of the electric intensity in the film because of an increase of h but by the shielding influence of the space charge of diffusing ions and electrons in that oxide film. With that purpose in view, the Debye shielding distance for plasma substance state in the oxide film was taken into consideration. The logarithmic law of oxide film growth was derived. Estimated calculations of this law’s parameters were made that quantitatively correspond with literature data. The results obtained were u.
Reoxidation and deactivation of supported cobalt Fischer-Tropsch catalysts

The role of water in the deactivation of Al2O3-supported cobalt Fischer−Tropsch catalysts has been studied at different water partial pressures. In addition, model studies at nonreacting conditions using H2O/H2 feeds were carried out in order to study the possible reoxidation of cobalt by water. High-pressure gravimetry, temperature-programmed reduction (TPR), and X-ray photoelectron spectroscopy (XPS) were used as characterization methods in the model studies. The kinetic studies showed significant deactivation when water was added to the feed in fixed-bed reactor experiments. In the model studies, a large extent of bulk cobalt reoxidation was only observed in the absence of H2. Only a small amount of reoxidation could be observed when H2 was present, even at high H2O/H2 ratios. However, XPS studies indicated significant surface oxidation of cobalt at a lower H2O/H2 ratio. Surface oxidation or oxidation of highly dispersed cobalt phases is therefore concluded to be responsible for the observed deactivati.
Inhibitory effect of ursane-type triterpenoids from Weigela subsessilis on RANKL-induced osteoclast differentiation

Osteoclasts play an important role in bone metabolism by resorbing the bone matrix. Thus, the compounds inhibiting osteoclasts can treat bone diseases such as osteoporosis. Among the 8 triterpenoids tested, we show that Ilekudinol B isolated from the plant Weigela subsessilis inhibits receptor activator of NF-κB ligand (RANKL)-induced osteoclastogenesis from bone marrow-derived monocyte/macrophage cells in a dose-dependent manner, whereas it has no significant effect on osteoblast differentiation. Furthermore, Ilekudinol B attenuates the induction of nuclear factor of activated T cells (NFAT) c1 and osteoclast-associated receptor (OSCAR) expression. Our results indicate that Ilekudinol B has the potential to inhibit osteoclast formation by attenuating the signaling cascades associated with RANKL. Key words: Triterpenoids, osteoclastogenesis, receptor activator of NF-κB ligand (RANKL), inhibitory activity.
Excess noise in amorphous selenium p‐i‐n devices

We report on 1/f noise measurements in amorphous selenium p-i-n devices, where the p- and n-layers are trapping layers for electrons and holes respectively. Under forward bias, the normalized 1/f noise power is 5 × 104 times less than that of a single i-layer device. At frequencies above 100 Hz, a region of white noise is observed that we attribute to partial shot noise. We propose that the reduction in 1/f noise and the region of shot noise are a result of the trapping layers acting as reservoirs of charge carriers. The traps randomize the charge carriers producing the observed white noise and act as the source of the device current. Sourcing the current in this way suppresses the very noisy charge injection from the metal electrodes which controls the current in single i-layer devices (© 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)
Precise/ Small Sample Size Determinations of Lithium Isotopic Compositions of Geological Reference Materials and Modern Seawater by MC‐ICP‐MS

The Li isotope ratios of four international rock reference materials, USGS BHVO‐2, GSJ JB‐2, JG‐2, JA‐1 and modern seawater (Mediterranean, Pacific and North Atlantic) were determined using multi‐collector inductively coupled plasma‐mass spectrometry (MC‐ICP‐MS). These reference materials of natural samples were chosen to span a considerable range in Li isotope ratios and cover several different matrices in order to provide a useful benchmark for future studies. Our new analytical technique achieves significantly higher precision and reproducibility (< ± O.3%o 2s) than previous methods, with the additional advantage of requiring very low sample masses of ca. 2 ng of Li.
QSAR Study of Aromatic Organochalcogens with Glutathione Peroxidase – like Antioxidant Activity

The molecular orbital energies and atomic Electron Densities (ED) of compounds that mimic the action of Glutathione Peroxidase (GPx), such as derivatives of α-(phenylselenenyl) keton (PhSeR1) and aromatic organochalcogens [YPh(X)1–2PhY], were calculated by ab initio Hartree-Fock/3-21G (d)gas basis set. Single and multiple linear regression models for two types of aromatic chalcogens were obtained with R2>0.75 and >0.63. For the α-(phenylselenenyl) keton and derivatives that react with Glutathione (GSH) via mixed selenenyl-sulfide compounds (RSeSG), a high correlation was obtained between the calculated LUMO (PhSeR1) energies and experimentally measured GPx like antioxidant activities. Thus, it is recommended to use the LUMO (PhSeR1) energies of novel derivatives (PhSeR1) of α-(phenylselenenyl) keton in the prediction of GPx like catalytic antioxidant activities. For the aromatic organochalcogens [YPh(X)1–2PhY] that react with GSH mainly via chalcogen-oxide intermediates, the Electrochemical Oxidation Potential (Epa) values on the glassy carbon electrode in aqueous media, the HOMO [YPh(X)1–2PhY] energies, and the ED on chalcogens [ED(X)] were selected as good predictors of GPx like catalytic antioxidant activities.
Observations and assessment of iron oxide and green rust nanoparticles in metal-polluted mine drainage within a steep redox gradient

Environmental context Legacy contamination from mining operations is a serious and complex environmental problem. We examine a former uranium mine where groundwater leaving the site enters a stream with chemically dramatic effects resulting in a fundamental change in the way contaminant metals are transported to the surface environment. The results are important for our understanding of how these contaminants are dispersed, and how they could interact with the biosphere. Abstract In this study of iron- and silica-bearing nanoparticle and colloid aggregates in slightly acidic mine drainage, we combined bulk scale geochemistry techniques with detailed nanoscale analyses using high-resolution transmission electron microscopy (HR-TEM) to demonstrate the complexity of iron oxide formation and transformation at a steep redox gradient (groundwater outflow into a stream), and the resulting role in metal(loid) uptake. We also identified pseudohexagonal nanosheets of Zn-bearing green rust in outflowing groundwater using HR-TEM. This is only the second study where green rust was identified in groundwater, and the second to examine naturally occurring green rust with analytical TEM. In aerated downstream waters, we found aggregates of poorly crystalline iron oxide particles (20–200nm in diameter). Inductively coupled plasma–mass spectrometry (ICP-MS) analysis of water fractions shows that most elements such as Ni and Zn were found almost exclusively in the dissolved–nanoparticulate (<0.1μm) fraction, whereas Cu and As were primarily associated with suspended particles. In the underlying sediments composed of deposited particles, goethite nanoneedles formed on the ferrihydrite surfaces of larger aggregated particles (100–1000nm), resulting in more reactive surface area for metal(loid) uptake. Sequential extraction of sediments showed that many metal(loid)s, particularly As and Zn, were associated with iron oxides identified as ferrihydrite, goethite and possibly schwertmannite. Amorphous silica co-precipitation with iron oxides was prevalent at all sampling sites, but its effect on metal(loid) sorption is unknown. Fine-grained iron oxide sediments are easily remobilised during turbulent flow events, adding to the mobility of the associated metals.
Corrosion potential and cathodic reduction efficiency of stainless steel in natural seawater

Stainless steels are widely used for different applications in seawater in the oil and gas and desalination industries. It is well known that the corrosion potential of stainless steel shifts to the noble direction (ennoblement) when exposed to natural seawater. The other significant effect of the biofilm on metallic surfaces is a dramatic increase of the cathodic reduction efficiency (e.g. cathodic reduction of dissolved oxygen), promoting the corrosion reactions and increasing the rate of corrosion propagation. Although, this has been widely studied in natural seawater at temperature ranging from 15 to 40 °C, very little is known on the effect of temperature (in a wider temperature range), dissolved oxygen content and chlorination level on the corrosion potential and the cathodic reduction efficiency of stainless steel in natural seawater. In this paper, corrosion potential and cathodic reduction efficiency of stainless steel are reported as a function of temperature (e.g. from 5 to 70 °C), dissolved oxygen content (e.g. from 20 ppb to saturation) and chlorination level (from 0 to 0.5 ppm). The results are discussed in terms of risk for crevice corrosion and bi‐metallic corrosion when coupling to other materials. In addition results from exposure in tropical sea are presented and compared to that of temperate seawater heated at the same temperature.
Surface properties and antibacterial activity of quaternized polysulfones

Novel quaternized polysulfones (PSFs) with two ionic chlorine contents were investigated, namely, their morphology and antimicrobial activity. Atomic force microscopy (AFM) studies on their membranes showed ordered domains, in which pores and nodules of different sizes and intensities were distributed. The charge density of the quaternized PSFs and the history of the membranes formed from solutions in solvent/nonsolvent mixtures influenced the different aspects of the surface images. The adhesion of Escherichia coli ATCC 10536 and Staphylococcus aureus ATCCC 6538 microorganisms to solutions of the modified PSFs is discussed in correlation with the hydrophobic/hydrophilic properties of the studied polymers and microorganisms. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Effects of plastic film mulching cultivation under non-flooded condition on rice quality

Plastic film mulching cultivation under non-flooded condition (PFMC), a new high-efficiency and water-saving cultivation technique, has been adopted and developed in many regions of china since the 1980s. Field experiments were conducted to evaluate the effects of PFMC on rice quality in three agro-ecosystems (plain, basin and mountainous area) in 2001. The experiment consisted of three treatments, which were conventional flooded cultivation (CFC), PFMC and non-mulching cultivation (NMC) under non-flooded condition in a randomized complete block design with three replications. Compared with CFC, PFMC increased head-milled rice recovery (with the exception of plain area), rice transparency and alkali spreading value, but slightly decreased gel consistency and obviously decreased chalky grain rate. Compared with NMC, those quality traits under PFMC were changeable at different sites. There were no significant differences for brown rice rate (except hilly area), milling rice quality and amylose content across treatments. In addition, nutritional quality under PFMC was notably improved in comparison with CFC and NMC. With few exceptions, the protein content, total amino acid content, individual amino acid content and Lys content of rice decreased in the order of PFMC > NMC > CFC. In general, rice quality is affected by each agro-ecosystem and cultivation system to different degrees. PFMC had more influence on rice quality in hilly region than plain and basin regions. Copyright © 2006 Society of Chemical Industry
INFLUENCE OF GUMS ON DOUGH PROPERTIES AND FLAT BREAD QUALITY OF TWO PERSIAN WHEAT VARIETIES

The effects of separate mixing of two hydrocolloids carboxymethylcellulose (CMC) and hydroxypropylmethylcellulose (HPMC) at 0.1, 0.3 and 0.5% levels with Sardary and Sorkheh wheat flours (two native Persian varieties) were studied. Chemical and rheological (Farinograph and Extensograph) tests, staling and sensory evaluations were performed on the two flours, their dough and the resulting Lavash flat bread, respectively. On the basis of split-plot experiment in a complete random design and using the Duncan's multiple range tests, the data were evaluated and the average of replicates was compared at the statistical level of 1% (α = 0.01). Although the CMC and HPMC gums enhanced significantly the dough quality of the two wheat varieties by increasing water absorption and reducing resistances after 90 and 135 min (compared with control), the effect of HPMC was more pronounced than CMC. Anti-staling properties of HPMC were better than CMC, especially for Sardary flour. Separate addition of 0.5% CMC and HPMC gums to Sorkheh and Sardary flours significantly delayed the staling process of the resulting Lavash bread by more than 45 and 42%, respectively. Additionally, sensory evaluation scores of the Lavash bread made from either Sorkheh flour containing 0.3% CMC or HPMC or Sardary flour containing 0.5% HPMC were 50 and 120% higher than control bread samples, respectively.
Instability of thin polymer films on coated substrates : Rupture, dewetting, and drop formation

Abstract We present a direct comparison of theoretical predictions and experimental results on instabilities and various stages of dewetting of thin ( 10 nm) polystyrene films, prepared on silicon wafers with three different nanosized (∼1 nm) coatings, dewet spontaneously above the glass transition temperature by the growth of cylindrical holes with wavy rims. We could clearly distinguish, and theoretically explain, four different stages as dewetting proceeded: (a) rupture of the film; (b) expansion and coalescence of holes to form a polygonal “cellular” pattern; (c) disintegration of polymer ridges forming the polygon into spherical drops due to Rayleigh instability; and (d) fingering instability of hole rims during hole expansion witnessed only on low wettability coatings. The theory gives a clear understanding of roles of substrate (silicon) wettability, coating wettability, and the film thickness in various stages (phenomena). For films much thicker than the coating, the wettability (contact angle) of the coated substrate by polystyrene has no influence on the initial length scale of the instability (number density of holes). This is explained by the dominating influence of long-range Lifshitz–van der Waals (LW) interactions originating from the bulk substrate; the LW and short-ranged polar interactions with the coating determine only the contact angle after appearance of an ultrathin three-phase contact zone (rupture). In stage b also, the final polygon diameters are rather independent of the coating, which is explained by insensitivity of stage a to the coating properties and a competition between the Rayleigh instability (leading to droplets) and drainage from ridges (leading, to coalescence). Hole growth, fingering instability, and the drop diameters, on the contrary, are highly affected by the surface properties (wettability) of coatings. An increase in the film thickness (h) decreases the number density of initial holes (αh−4), increases the polygon diameter (αh2), increases the drop diameter (αhq,qvaries from 1 to 1.5 depending on the contact angle), and makes the fingering instability stronger. Theory and experiment are in excellent qualitative and quantitative agreement. The theory also suggests several interesting possibilities for the design of future experiments on the dewetting of thin films.
The toxic effect of silver ions and silver nanoparticles towards bacteria and human cells occurs in the same concentration range

Silver is commonly used both in ionic form and in nanoparticulate form as a bactericidal agent. This is generally ascribed to a higher toxicity towards prokaryotic cells than towards mammalian cells. Comparative studies with both silver ions (such as silver acetate) and polyvinylpyrrolidone (PVP)-stabilized silver nanoparticles (70 nm) showed that the toxic effect of silver occurs in a similar concentration range for Escherichia coli, Staphylococcus aureus, human mesenchymal stem cells (hMSCs), and peripheral blood mononuclear cells (PBMCs), i.e. 0.5 to 5 ppm for silver ions and 12.5 to 50 ppm for silver nanoparticles. For a better comparison, bacteria were cultivated both in Lysogeny broth medium (LB) and in Roswell Park Memorial Institute medium (RPMI)/10% fetal calf serum (FCS) medium, as the state of silver ions and silver nanoparticles may be different due to the presence of salts, and biomolecules like proteins. The effective toxic concentration of silver towards bacteria and human cells is almost the same.
Physiological and mineralogical properties of arsenic-induced chlorosis in rice seedlings grown hydroponically

Abstract A hydroponic experiment was conducted to observe the effect of arsenic (As) on a number of physiological and mineralogical properties of rice (Oryza sativa L. cv. Akihikari) seedlings. Seedlings were treated with 0, 6.7, 13.4 and 26.8 µmol L−1 As (0, 0.5, 1.0 and 2.0 mg As L−1) for 14 days in a greenhouse. Shoot dry matter yield decreased by 23, 56 and 64%; however, the values for roots were 15, 35 and 42% for the 6.7, 13.4 and 26.8 µmol L−1 As treatments, respectively. Shoot height decreased by 11, 35 and 43%, while that of the roots decreased by 6, 11 and 33%, respectively. These results indicated that the shoot was more sensitive to As than the root in rice. Leaf number and width of leaf blade also decreased with As toxicity. Arsenic toxicity induced chlorosis symptoms in the youngest leaves of rice seedlings by decreasing chlorophyll content. Concentrations and accumulations of K, Mg, Fe, Mn, Zn and Cu decreased significantly in shoots in the 26.8 µmol L−1 As treatment. However, the concentration of P increased in shoots at 6.7 and 13.4 µmol L−1 As levels, indicating a cooperative rather than antagonistic relationship. Arsenic and Fe concentration increased in roots at higher As treatments. Arsenic translocation (%) decreased in the 13.4 and 26.8 µmol L−1 As treatments compared with the 6.7 µmol L−1 As treatment. Arsenic and Fe were mostly concentrated in the roots of rice seedlings, assuming co-existence of these two elements. Roots contained an almost 8–16-fold higher As concentration than shoots in plants in the As treatments. Considering the concentration of Mn, Zn and Cu, it was suggested that chlorosis resulted from Fe deficiency induced by As and not heavy-metal-induced Fe deficiency.
Corrosion and Scale Inhibition Properties of Sodium Lignosulfonate and Its Potential Application in Recirculating Cooling Water System

The corrosion and scale inhibition properties of sodium lignosulfonate (SL) were investigated by determining the corrosion and scale inhibition efficiency, the polarization curve, the residual turbidity, and the polymorph of calcium carbonate (CaCO3) scale. It is found that, to a certain degree, SL has a positive corrosion inhibition effect at the higher dosage, whereas it accelerates the corrosion of carbon steel at the lower dosage. SL also has a good dispersibility to CaCO3, causing a small CaCO3 scale inhibition efficiency of maximum value of 2.5% at a dosage of 50 mg/L SL. Because there exist intrinsic limitations of SL without modification as a water treatment agent in a cooling water circulation system, the original SL was further chemically modified by grafting with acrylic acid monomer. The modified SL increases its negative charge density and hence an adsorption quantity on the active anodic sites in the electrochemical reaction. The corrosion inhibition efficiency of modified SL is consequently.
Overcoming Underrepresentation in Clinical Datasets for Accurate Subpopulation-specific Prognosis

Clinical datasets are intrinsically imbalanced, dominated by overwhelming majority groups. Off-the-shelf machine learning models optimize the prognosis of majority patient types (e.g., healthy class), causing substantial errors on the minority prediction class (e.g., disease class) and minority subpopulations (e.g., Black or young patients). For example, missed death prediction is 36.6 times higher than non-death cases in a mortality benchmark. Racial and age disparities also exist. Conventional metrics such as AUC-ROC do not reflect these deficiencies. We design a double prioritized (DP) sampling technique to improve the accuracy for underrepresented subpopulations. We report our findings on four prediction tasks over two clinical datasets, and comparisons with eight existing sampling solutions. With DP, the recall of minority classes shows 35.4-130.4% improvement. Compared to the state-of-the-arts, DP sampling gives 1.2-58.8 times more balanced recalls and precisions. Our method trains customized models for specific race or age groups, a departure from the one-model-fits-all-demographics paradigm. As underrepresented groups in clinical medicine are a daily occurrence, our contributions likely have broad implications.
The White Wine Mouthfeel Wheel: A Lexicon for Describing the Oral Sensations Elicited by White Wine

Abstract White wines can elicit a wide range of taste and mouthfeel sensations, some of which may be qualitatively different to those elicited by red wine. Through extensive sensory panel work involving 136 wines and 21 sessions, a lexicon, set of definitions, evaluation protocol and reference standards have been developed to describe and measure the oral sensations elicited by white wine, including table, sparkling, dessert and fortified styles. The lexicon has been visualised as a hierarchical wheel structure. These tools can be used to more fully define the influence of viticultural and oenological variables on white wine quality and to aid in the training of and communication between wine professionals.
A model investigation of ab initio geometries for identity and nonidentity substitution with three-center four- and three-electron transition states

With the van't Hoff model derived from the dynamics of a regular tetrahedron in which the interstitial carbon changes its position from tetrahedral into a trigonal (bi)pyramidal configuration, the introduction of dimensionless ratio numbers (R) can serve to localize significant points on the principal reaction coordinate. These numbers are expressed as R(d) and R(n) based on transition state geometries and the number of electrons involved in the three-center bonding, respectively. Using this concept, we obtain a model for the evaluation of different ab initio calculations based on identity and nonidentity substitution reactions for three-center four- and three-electron bonding transition states. Similar ratio numbers have been derived for proton exchange reactions. The reactions under investigation show clearly that in spite of the differences in chemical outcome the transition steps reduced to the first principles of chemical bonding are similar. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011