Miracle-dz/UniFAR-FTUs huggingface dataset:
Oxidation Stability of Palm Methyl Ester: Effect of Metal Contaminants and Antioxidants

The European biodiesel standard EN-14214 calls for determining the oxidation stability (OS) at 110 °C with a minimum induction time of 6 h by the Rancimat method (EN-14112). The ASTM standard D-6751 has recently introduced a minimum induction period of 3 h. Palm methyl ester (PME) has been successfully evaluated as a diesel substitute in summer and with an additive in winter due to its poor cold-flow properties. Neat PME exhibited an OS of 9.24 h; thus, it was highly stable. Research was conducted to investigate the effect of the presence of transition metals, likely to be present in the metallurgy of storage tanks and barrels, on the highly stable PME. It was found that the influence of metal was detrimental and catalytic even for stable PME. Small concentrations of metal contaminants showed nearly the same influence on OS as large amounts. Copper showed the strongest detrimental and catalytic effect. Antioxidants, namely, tert-butylated hydroxytoluene (TBHT), tert-butylated phenol derivative (TBP), octy.
Enzymatic Molecular Mechanism of the Human O-GlcNAcase to Design New Inhibitors: A Quantum Mechanical Approach

In this study the catalytic mechanism of O-glycoprotein 2-acetamino-2-deoxy-β-D-glucopyranosidase (O-GlcNAcase) has been studied by using density functional theory (DFT) at the B3LYP level and split-valance 6-311G** basis set. The results indicate that the reaction path takes place in a two-step mechanism. In the first step, Asp174 polarizes the 2-acetamido group, which makes it act as a catalytic nucleophile to form the oxazoline intermediate. In the following step, Asp175 acts as a general base to promote the attack of one water molecule at the anomeric center to produce the β-hemiacetal product. This reaction path involves two transition states (Ts1 and Ts2) and one intermediate.
A novel STI etching technology to mitigate an inverse narrow width effect, and improve device performances for 90 nm node and beyond CMOS technology

A new STI (shallow trench isolation) with automatic top corner rounding (ATCR) to improve 90 nm CMOS narrow width device performance has been studied in detail. Experimental results show that the ATCR mitigates the inverse narrow width effect, and increases the driving current (Idsat) by 8% together in a unit process step, thus getting easy process control and cost down benefits, which cannot be achieved through conventional methods. Additionally, the ATCR attained a better trench depth uniformity, and thus a wider process window (20–50 s) than that of the conventional method. Furthermore, the technique does not degrade the gate oxide integrity and junction leakage current; thus the developed ATCR STI technique is more suitable for 90 nm and beyond narrow width CMOS technologies.
Experiments with back side gas cooling using an electrostatic wafer holder in an electron cyclotron resonance etching tool

Wafer temperature, etch rate, and etch uniformity measurements of SiO2 wafers were made to characterize the use of back side helium cooling with an electrostatic wafer holder in an electron cyclotron resonance etching tool. The etch rate was found to be independent of the wafer temperature in the range between 20 and 110 °C. A 7% increase in etch nonuniformity (3σ) at higher backside pressures was attributed to helium, which leaked around the edge of the wafer, displacing the etchant gas. A back side pressure of 2–3 Torr provides a balance between wafer temperature control and helium leak rates.
Elastic Properties of Eucalyptus pilularis Sm. Perpendicular to the Grain. II. In Compression

On examine les effets de la teneur en humidite et de la densite sur la contrainte et la deformation a la limite de proportionnalite, sur la contrainte et deformation a la rupture et sur le module d'elasticite en traction perpendiculaire au grain du bois d'Eucalyptus pilularis
Adsorption of Cu ions onto a 1.10 phenanthroline-grafted brazilian bentonite

The grafting, by chemical adsorption, of molecular 1.10-phenanthroline (OP) onto some Brazilian bentonite (montmorillonites) was studied to improve their adsorptive capacities to remove Cu ions from synthetic wastewater. The quantity of OP adsorbed was 112 mg g−1 of bentonite at pH 8.5 and no significant desorption was detectable in acidic or basic solutions. X-ray diffraction (XRD) spectra show that a complex type-β is formed in which the OP molecules lay inclined in the clay interlayer. After the intercalation of OP, the adsorptive capacities of the natural bentonites increased by a factor of ten. Thus, adsorption of Cu ions, at optimal pH of 8.0±0.5, showed saturation values, which, calculated by the Langmuir model, yielded 110 mg of Cu ions g−1 of bentonite (3.5 meq g−1). The mechanisms of Cu uptake are ion-exchange adsorption onto untreated bentonite and ion exchange plus Cu2+ phenanthroline complexation (chemisorption) on the modified pillared clay. The desorption of Cu ions from OP clay revealed high uptake irreversibility and physical stability (of the adsorbent) either in strongly acidic or basic solutions. Thus, after acid treatment ∼90% of the adsorbed Cu ions continued to be bound onto the OP-modified bentonite surface.
Development of Cotton Fabric with Antibacterial Properties: Part I: Preparation of Poly(acrylamide‐co‐itaconic acid) grafted Cotton Fabric and its Water Uptake Analysis

Graft co‐polymerization of monomers acrylamide (AAm) and itaconic acid (IA) on to cotton fabric has been carried out in aqueous medium using ceric ammonium nitrate as initiator under the catalytic activity of nitric acid. The cotton fabric was optimally initiated in 20 mM aqueous solution of initiator for 15 min, followed by its immersion in aqueous solution containing of monomers AAm and IA, and cross‐linker N,N′‐methylene bisacrylamide (MB)at 30°C. To obtain optimum conditions, the percent grafting was investigated as a function of concentration of the monomers, the cross‐linker and the initiator, reaction temperature and time of immersion for initiation. The grafted cotton fabric was also investigated for its water uptake behavior.
The inflow of uranium 234U and 238U from the Vistula River catchment area to the Baltic Sea

Abstract In the study, the activities of uranium 234U and 238U in the Vistula River water samples which were collected from November 2002 to October 2003, were measured using alpha spectrometry. In winter, the highest concentration of uranium isotopes and total uranium was in the Vistula River water from Malbork (13.13±0.22 Bq m−3 for 234U, 12.45±0.21 Bq m−3 for 238U and 1.02±0.30 mg m−3 for total uranium), and the lowest was in water from Dęblin (1.73±0.07 Bq m−3 for 234U, 1.55±0.07 Bq m−3 for 238U and 0.13±0.09 mg m−3 for total uranium). In analyzed river samples uranium isotopes 234U and 238U are not in the radioactive equilibrium state. The values of 234U/238U activity ratio lie between 1.05–1.70. During spring, the highest concentration of uranium isotopes and total uranium was found in the Vistula River water from Malbork (12.36±0.19 Bq m−3 for 234U, 10.77±0.17 Bq m−3 for 238U and 0.88±0.25 mg m−3 for total uranium), and the lowest was in water taken from Sandomierz (5.77±0.14 Bq m−3 for 234U) and Kraków (4.08±0.11 Bq m`−3 for 238U and 0.33±0.18 mg m−3 for total uranium). The values of 234U/238U activity ratio lie between 1.15–1.64. In summer, the highest concentration of uranium isotopes and total uranium was found in the Vistula River water samples taken from Malbork (8.22±0.21 Bq m−3 for 234U, 7.60±0.21 Bq m−3 for 238U and 0.62±0.29 mg m−3 for total uranium), and the lowest was in water from Sandomierz (6.37±0.12 Bq m−3 for 234U) and Kraków (3.56±0.19 Bq m−3 for 238U and 0.29±0.33 mg m−3 for total uranium). The values of 234U/238U activity ratio lie between 1.08–1.95. In autumn the highest concentration of uranium isotopes and total uranium was in the Vistula River water from Malbork (17.80±0.25 Bq m−3 for 234U, 15.12±0.23 Bq m−3 for 238U and 1.23±0.34 mg m−3 for total uranium) and the lowest was in water from Toruń (8.15±0.49 Bq m−3 for 234U) and Kraków (6.34±0.47 Bq m−3 for 238U and 0.52±0.78 mg m−3 for total uranium). The values of 234U/238U activity ratio lie between 1.10–1.74. Annually, the southern Baltic Sea is enriched by about 507 GBq uranium isotopes 234U and 238U, with 490 GBq going to the Gdańsk Bay and 16.5 GBq to Vistula Lagoon. The highest surface 238U runoff was observed in spring (to 1200 kBq km−2 quarter−1 for catchment´s area), the lowest in summer for Bug with Narew catchment´s area to 20 kBq km−2 quarter−1). These studies are very important for the inflow estimation of natural and anthropogenic alpha radionuclides to the Baltic Sea.
A Study to Assess the Knowledge Regarding PCOS (Polycystic Ovarian Syndrome) among Nursing Students at NUINS.

: Polycystic ovarian syndrome is an endocrine disorder which affects the adolescent girls. It has been found through studies that it affects around 5% to 10% of women in their reproductive years. The study was conducted to assess the knowledge on the polycystic ovarian syndrome among the student nurses. The data was collected from the nursing students by using structured questionnaire. The data collected from 150 samples in Nitte Usha Institute of Nursing Sciences. Descriptive survey research approach was adopted and data was analyzed by using descriptive and inferential statistics. Distribution of the samples on demographic characteristics revealed that 85% of the samples were in the age group of 21-25years, 75% of the samples were Christians, 82% of the samples were consuming mixed diet, and 92% samples had regular menstrual cycle. 76% of the samples were with average knowledge and 10.7% with good knowledge regarding polycystic ovarian syndrome. Hence the study concluded that Source of information, consumption of junk food, dietary patterns of the students were associated with their level of knowledge on PCOS at 5% level of significance.
Fluorescence quenching of polycyclic aromatic compounds by humic acid

Single- and multi-channel stationary and time-resolved fluorescence measurements on selected polycyclic aromatic compounds (PAC) were performed to obtain photo-physical information about fluorophore/soil interactions. The fluorescence properties of anthracene, pyrene and phenanthrene in the presence of Aldrich humic acid in water were investigated with stationary and time-resolved fluorescence measurements. For all three PACs, fluorescence quenching was dominated by static quenching processes; dynamic quenching played only a minor role. It was found that the static quenching of phenanthrene fluorescence was significantly less efficient than the fluorescence quenching of anthracene and pyrene. The Stern–Volmer analysis showed a significant effect of pH on static quenching of anthracene and pyrene fluorescence; e.g., at pH 2, quenching of pyrene fluorescence was approximately three times more effective than at pH 12. This effect could be explained by the pH–dependent macromolecular structure of humic acids. For the dynamic quenching of pyrene fluorescence, no pH dependence was discernible and a Stern–Volmer constant of KSV= 3 × 10–3 l mg–1 was obtained. The experimentally determined Stern–Volmer constants for dynamic and static fluorescence quenching were taken to estimate an average molar mass of the humic acid used and to assess the pH-dependent organic carbon-normalized partition coefficients KOC.
Stress Corrosion and Hydrogen Embrittlement in an Aluminum Alloy

Abstract A strain aging type of reversible hydrogen embrittlement has been demonstrated for a high strength aluminum alloy in a 3% NaCl environment. Permeation of hydrogen was related to SCC under cathodic polarization as well as anodic conditions. Internal friction and lattice parameter measurements relate directly to lattice dissolved hydrogen arising from the environment. It is concluded that the evidence is quite consistent with a mechanism of stress corrosion cracking (SCC) involving absorption of hydrogen leading to lattice dissolved hydrogen and embrittlement.
EPR and ENDOR Studies of Deuteron Hyperfine and Quadrupole Coupling in •CD(COOD)2: Experimental and Theoretical Estimates of Electric Field Gradients from an α-Carbon

In single crystals of malonic acid grown from heavy water, the methylene protons have been partially exchanged with deuterons. Upon X irradiation at room temperature, the (CD)-C-. (COOD)(2) radical is formed in an amount comparable to the (CH)-C-. (COOD): radical species. In the present work, EPR and ENDOR analyses of the a-deuteron hyperfine coupling (hfc) and nuclear quadrupolar coupling (nqc) tensors at room temperature have been performed. The hyperfine coupling tensor is, when scaled with the differences in the nuclear g-factor, almost identical to the a-proton coupling of the (CH)-C-. (COOH)(2) radical at room temperature. The quadrupolar coupling tensor was found to be virtually coaxial with the hyperfine coupling tensor. The quadrupolar coupling constant is 149.8 +/- 1 kHz, and the asymmetry factor eta = 0.092 +/- 0.020. It is known that, at room temperature, the malonic acid radical exhibits thermal motion between two potential energy minima separated by about +/-12 degrees. Assuming that the observed hfe and nqc tensors are the result of thermal avenging between these two conformations of the radical, a simple two-site jump model was used to estimate the rigid-limit tensors. The most significant result obtained was for the nyc tensor, for which the calculations resulted in a quadrupolar coupling constant of 160 kHz and an asymmetry factor eta = 0.026. These values are fairly close to the nqc parameters for the methylene deuterons in malonic acid at low temperature. The quadrupolar coupling tensor has been theoretically modeled using Slater orbitals and formal electronic populations, as well as electron populations obtained from RHF/CI INDO-type calculations. The simple model to compute the electric field gradient at the alpha-deuteron caused by the charge distribution at the sp(2)-hybridized alpha-carbon was found to be as successful as more advanced methods. Furthermore, density functional theoretical (DFT) calculations for both the malonic acid radical and the native malonic acid molecule have been performed. Field gradients calculated by the DFT method significantly overestimate the quadrupolar tensors for both the alpha-deuteron of the radical and the methylene deuterons of the malonic acid molecule. Calculations using electron populations from the RHF/CI INDO calculations show that contributions to the quadrupolar coupling tensor from electrons and nuclei beyond the nearest-neighbor atom of the Jeuteron are significant.
Crystalline phases related to a decagonal quasicrystal. I. A single‐crystal X‐ray diffraction study of the orthorhombic Al3Mn phase

Al3Mn (with the stoichiometric composition Al28.1Mn10.9), M(r) = 1356.5, orthorhombic, Pn2(1)a, a = 14.837 (4), b = 12.457 (2), c = 12.505 (2) angstrom, V = 2311.2 (8) angstrom3, atoms/cell = 4 x 39, D(x) = 3.90 g cm-3, lambda(Mo Kalpha) = 0.71069 angstrom, mu = 65.82 cm-1, F(000) = 2550.15, room temperature, R = 0.068 for 1289 reflections. About two-thirds of Mn atoms have icosahedral coordination. In a repeat unit b, there are four interpenetrated icosahedra with two Mn and two Al atoms at their centers. This phase has a layer structure consisting of an almost 'flat' layer F sandwiched between two puckered P and p layers in the sequence PFpP'F'p'. , where P'F'p' and PFp are related by the 2(1) axes parallel to [010]. A similar layer structure has also been found in the pi-AlMnM (M = Ni, Cu, Zn) phases. Both these two crystalline structures can be obtained from that of the Al-Mn decagonal quasicrystal by substituting a rational ratio of two consecutive Fibonacci numbers for the irrational tau = [1 + (5)1/2]/2 in the two quasiperiodic directions.
Infrared and Raman Spectra of Carbon Suboxide in Condensed Phases

Infrared and Raman spectra of liquid, crystalline, and matrix‐isolated carbon suboxide have been obtained in the region 20–4000 cm−1. A previously unreported solid—solid transition has been observed at 115°±5°K, and possible structures for both crystalline phases have been inferred from the spectroscopic results. The πu central‐carbon bending mode ν7 has been identified in the liquid phase at 72±2 cm−1. The problem of ``disappearing'' sum bands is discussed, and a revised vibrational assignment and force‐constant analysis for carbon suboxide is presented.
Comparative assessment of the ELBA coarse-grained model for water

The ELBA force field for water consists of a single spherical site embedded with a point dipole. This coarse-grained model is assessed here through the calculation of fundamental properties of bulk liquid water and the water–vapour interface. Accuracy and efficiency are evaluated and compared against simulations of standard three- and four-site atomistic models. For bulk liquid systems, ELBA reproduces accurately most of the investigated properties. However, the radial distribution function deviates from atomistic and experimental data, indicating a loss of local structure. The water–vapour interface, simulated over a range of temperatures from 300 to 600 K, is captured realistically in terms of its density distribution, and the accuracy in reproducing the experimental surface tension is as high as that of the best atomistic model. The critical temperature of ELBA is also found to be in excellent agreement with experiment. However, the interfacial electric field and surface potential are missing. The computational speed-up of ELBA compared to traditional atomistic models is estimated to be between one and two orders of magnitude.
Comparison of chemical methods and immunoassay for the detection of pesticide residues in various matrices

The synthetic pyrethroid permethrin has widespread use in agriculture and, as a result, is found in a variety of matrices. Chemical methods based on gas chromatography/mass spectrometry operated in the negative chemical ionization mode (GC‐NCI/MS) have been developed. Sample extraction techniques such as ultrasonication and steam distillation have also been examined. Significant improvements have been made, compared with traditional methods, in both sample extraction time and detection level for a range of matrices. Enzyme‐linked immunosorbent assay (ELISA) methods have also been developed for permethrin. This study addresses the comparison of ELISA and chemical assays for permethrin in a variety of both environmental and laboratory‐spiked samples. The sensitivities, specificities and potential applications of these methods are discussed.
Determination of Bisphenol-A in Reusable Polycarbonate Food-Contact Plastics and Migration to Food-Simulating Liquids

Bisphenol-A (BPA) is a principal reactant in the preparation of polycarbonate (PC) plastics and has been shown in in vitro cell proliferation studies to exhibit estrogen-like characteristics. Reusable baby bottles, water carboys, and other housewares are often made of PC. A high-pressure liquid chromatographic (HPLC) protocol was used to determine residual BPA in PC and BPA migrated to food simulants in contact with PC under controlled time/temperature conditions. Confirmation of BPA was performed by gas chromatography/mass spectrometry (GC−MS). Residual amounts of BPA found in PC food contact articles ranged from 7 to 58 μg/g. In migration tests the plastic was exposed to water, ethanol/water mixtures, and Miglyol (a food oil simulant) in sealed vials at a constant temperature of 65 °C, for up to 10 days. BPA in food simulants ranged from 13 to 368% of BPA available to migrate from the polymer. GC−MS methods were applied to the analysis of water stored in reusable PC 5-gal water carboys. The amount of BP.
The Kinetics of Ethanol Production from Cane Molasses by Saccharomyces cerevisiae in a Batch Bioreactor

The present study was aimed at achieving a better understanding about fermentation condition by Saccharomyces cerevisiae with cane molasses for bioethanol production. The biosynthesis of ethanol was conducted via S. cerevisiae from cane molasses at pH 4.5 and 30°C. The fermentation was carried out in triplicate with various feed concentrations of molasses for S. cerevisiae in a batch bioreactor. S. cerevisiae produced ethanol at 9.3 ± 1.8 g/l with a biomass yield of 0.57 g/g after 36 h. The kinetic of growth dependence on molasses was represented by Andrew equation to predict the inhibition constant in the cultures media.
Crystal structure determination of Hägg carbide, χ-Fe5C2 by first-principles calculations and Rietveld refinement

Abstract X-ray powder-diffraction data recorded using different wave lengths as well as neutron powder diffraction data on Hägg carbide, χ-Fe5C2, were evaluated by Rietveld or Pawley refinements, respectively. Likewise, employing different starting models, first-principles calculations using density functional theory (DFT) involving structure optimisation with respect to energy were performed for χ-Fe5C2. The results from diffraction and DFT imply a crystal structure having a monoclinic C2/c symmetry with a quite regular (monocapped) trigonal-prismatic coordination of C by Fe atoms. The anisotropy of the microstrain broadening observed in the powder-diffraction patterns agrees with the anisotropy of the reciprocal Young’s module obtained from elastic constants calculated by DFT. The anisotropic microstrain broadening can to some degree, be modelled allowing for a triclinic distortion of the metric of χ-Fe5C2 (deviation of the lattice angle γ from 90°) involving reflection spitting, which mimics the hkl-dependently broadened reflections. This distortion corresponds to the most compliant shear direction of the monoclinic χ-Fe5C2. The anisotropic microstrain broadening results from microstress induced e.g. by anisotropic thermal expansion inducing misfit between the grains, in association with the intrinsic anisotropic elastic compliance of χ-Fe5C2. This anisotropic microstrain broadening was likely the origin of previous proposals of triclinic P-1 space-group symmetry for the crystal structure of χ-Fe5C2, which is rejected in the present work.
Ethynylene‐containing donor–acceptor alternating conjugated polymers: Synthesis and photovoltaic properties

Four ethynylene-containing donor-acceptor alternating conjugated polymers P1–P4 with 2,5-bis(dodecyloxy) substituted phenylene or carbazole as the donor unit and benzothiadiazole (BTZ) as the acceptor unit were synthesized and used as donor polymers in bulk heterojunction polymer solar cells. The optical, electrochemical, and photovoltaic properties of these four polymers with the ethylene unit located at different positions of the polymer chains were systematically investigated. Our results demonstrated that absorption spectra and the HOMO and LUMO energy levels of polymers could be tuned by varying the position of the ethynylene unit in the polymer chains. Photovoltaic devices based on polymer/PC71BM blend films spin coated from chloroform and dichlorobenzene solutions were investigated. For all four polymers, open circuit voltages (Voc) higher than 0.8 V were obtained. P4, with ethynylene unit between BTZ and thiophene, shows the best performance among these four polymers, with a Voc of 0.94 V, a Jsc of 4.2 mA/cm2, an FF of 0.40, and a PCE of 1.6%. © 2012 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem, 2013