Miracle-dz/UniFAR-FTUs huggingface dataset:
Bulk and Surface Mechanical Properties of Clay Modified HDPE used in Liner Applications

High-density polyethylene (HDPE)/clay nanocomposites were prepared by melt blending process. The HDPE was mixed with different organoclays and polyethylene-grafted-maleic anhydride was used as a compatibiliser. A masterbatch procedure was used to obtain final organoclays concentrations of 1, 2.5 and 5 wt%. The effects of various types of nanoclays and their concentrations on morphological, thermal and mechanical properties of nanocomposites were investigated. Surface mechanical properties such as instrumented nanohardness, modulus of elasticity and creep were also measured using a nanoindentation technique. Young's, storage and loss moduli, were found to be higher than that of the neat polymer at low loading (2.5 wt%) for clay Cloisite 15A and at higher loading (5 wt%) for clay Nanomer 1.44P. The ultimate strength and the toughness decreased slightly compared to pure HDPE. The differential scanning calorimetry analysis revealed that the peak temperature of the nanocomposites increased with increased clay content while the crystallinity decreased. Also, dynamic mechanical analysis revealed the storage and loss moduli are enhanced by addition of nanoclay. Both mechanical and thermal properties of HDPE/Nanomer 1.44P nanocomposite showed interesting trends. All properties first dropped when 1 wt% of the clay was added. Thereafter, a gradual increase or decrease then followed as the loading of Nanomer was increased. These trends were observed for all mechanical properties. The results obtained from nanoindentation tests for surface mechanical properties also showed similar trend to that of bulk measurements. Based on these measurements a nanoclay additive for a liner grade HDPE was selected. © 2011 Canadian Society for Chemical Engineering
Ferric complexes as catalysts for fenton degradation of 2,4-D and metolachlor in soil

Fenton-type reactions of hydrogen peroxide with Fe compounds generate bydroxyl radical (OH{center_dot}) or other reactive species and are potentially useful for degrading organic contaminants in soil. The use of simple Fe salts is limited, however. This study investigated certain pH 6-soluble Fe(III) complexes (Fe-L, where L is an organic tigand) as catalysts for degradation of herbicides 2,4-dichlorophenoxyacetic acid (2,4-D) and metolachlor (2-chloro-N-[2-ethyl 6-methylphenyl]-N-[2-methoxy-l-methylethyl]acetamide). Reactions were carried out in 1:1 aqueous suspensions of a topsoil (15.7 g kg{sup -1} organic C) at the natural pH of 5.7 with herbicides at concentrations representative of a spill (2-3 g kg{sup -1} about 0.01 mol kg{sup -1}). The two herbicides had contrasting sorption behavior in that 2,4-D was mostly in solution, whereas metotachlor was mostly sorbed. The best results were obtained using Fe-nitrilotriscetate (NTA) or Fe-hydroxyethyleniminodiacetate (HEIDA) at 0.01 mol kg-{sup -1} and [H{sub 2}O{sub 2}]{ge} 0.5 mol kg{sup -1}. The gallic acid complex was less effective. In 3 h,{sup 14}C-labeled 2,4-D was quantitatively dechlorinated and partially (15-30%) converted to {sup 14}CO{sub 2}: metolachlor was 93% transformed and 29% dechlorinated. Controls using free ligand plus peroxide or peroxide alone gave little or no reaction. Fe-L + H{sub 2}O{sub 2} was superior to the Fentonmore » reagent itself (Fe{sup 2+} + H{sub 2}O{sub 2}). The results of this study demonstrate that relatively mild chemical oxidation can be effective for remediation of certain contaminants in soil 23 refs., 2 figs., 6 tabs. « less
Wall Deposition of Ultrafine Aerosol Particles by Thermophoresis in Nonisothermal Laminar Pipe Flow of Different Carrier Gas

Deposition of ultrafine aerosol particles by Brownian diffusion and thermophoresis in a nonisothermal laminar pipe flow is investigated theoretically and experimentally. The deposition rates of Ag and TiO2 particles of 8–30 nm in diameter suspended either in N2, Ar or He gas are measured using a circular pipe with a nonuniform wall temperature distribution. The numerical calculation results considering the gas flow, temperature and particle distributions in the pipe show good agreement with the measured values. The particle deposition is enhanced with the increase of the wall temperature variation, but does not depend on the particle material. The difference in the deposition rates among the carrier gases is mostly attributable to the values of the Brownian diffusion coefficient. The enhancement of deposition by thermophoresis is of a similar magnitude among the carrier gases, which is explained in terms of the temperature distribution of the gases in the pipe.
Magnetochemistry of the tetrahaloferrate(III) ions. 1. Crystal structure and magnetic ordering in bis[4-chloropyridinium tetrachloroferrate(III)]-4-chloropyridinium chloride and bis[4-bromopyridinium) tetrachloroferrate(III)]-4-bromopyridinium chloride

A novel yellow salt of stoichiometry [4-Cl(py)H] 3 Fe 2 Cl 9 (where 4-Cl(py)H is 4-chloropyridinium, C 5 H 6 NCl) was shown by X-ray crystallograpahy [monoclinic lattice; space group P2 1 /n, a=14.736 (3) A, b=13.923 (3) A, c=14.740 (3) A, β=92.01 (2)°, Z=4, R(F o )=0.054 for 2719 independent reflections with |F 2 2 |>σ(F 2 )] to contain two slightly distorted tetrahedral [FeCl 4 ] − anions [r(FeCl)=2.179 A], one chloride anion, and three [4-Cl(py)H] + cations in the formula unit, all three cations being hydrogen bonded to the single chloride anion [r(H.Cl)=2.15 A]. For 2[4-Cl(py)H] [FeCl 4 ]•[4-Cl(py)H]Cl, the bicritical point is at 2.40 K and 7.0 kOe, and H SF (0)=5.5 kOe; with H c (0)=56 kOe, α=H A /H E =1.9×10 −2 . For 2[4-Br(py)H][FeCl 4 ]•[4.Br(py)]Cl, the bicritical point is at 2.24 K and 4.2 KOe and H SF (0)=3.0 kOe; with H c (0)=42 kOe, α=1.0×10 −2 . Both salts behave approximately as S=5/2, 3D Heisenberg antiferromagnets
Hydrosilation-Cured Poly(dimethylsiloxane) Networks: Intrinsic Contact Angles via Dynamic Contact Angle Analysis

A method for measuring intrinsic advancing (θadv) and receding (θrec) water contact angles is reported for hydrosilylation-cured poly(dimethylsiloxane) network coatings that are analogues of biomedical materials. Static and dynamic contact angle (DCA) methods were used to evaluate coatings prepared from commercial divinyl-terminated poly(dimethylsiloxane) (C-DVPDMS) and synthesized low polydispersity divinyl-terminated poly(dimethylsiloxane) (N-DVPDMS). DCA measurements showed that coatings prepared with both C-DVPDMS and N-DVPDMS contaminated the water surface during analysis. For ambient temperature cure, the rate of contamination was C-DVPDMS > N-DVPDMS. Methods for acquiring intrinsic contact angles on the PDMS coatings include using a large surface area reservoir or changing the water reservoir between DCA cycles. Intrinsic contact angles for hydrosilylation-cured PDMS coatings are as follows: θadv, 118°, θrec 83°; after contamination of the water surface the contact angles change to θadv, 108°, θre.
Spin fluctuation theory of nearly ferromagnetic metals

Based on the spin fluctuation theory, we propose a way to analyse the magnetic properties of nearly ferromagnetic metals by introducing quantities corresponding to the saturation magnetization in the ground state and the Curie temperature for weak ferromagnets. We also show how to evaluate the spin fluctuation parameters from experiments. As an example, magnetic properties of paramagnetic Y(Co1-xAlx)2 are discussed.
Synthesis of poly(vinyl alcohol) — hydroxyapatite composites and characterization of their bioactivity

A series of poly(vinyl alcohol) membranes reinforced with hydroxyapatite in various weight percent — 0%, 10%, 20%, 30%, 40% and 50% were prepared. Hydroxyapatite was prepared by a sol-gel procedure using diammonium hydrogen phosphate and calcium nitrate tetrahydrate as starting materials in an alkaline aqueous environment and then mixed with a solution of poly(vinyl alcohol), which was prepared by dissolving it in water at 85°C.The different mixtures were cast in a mould and evaporated for 7 days at a temperature of 30°C to obtain 1 mm thin membranes. FTIR spectroscopy was used to identify the different functional groups in the composites. The surface morphology was examined using a scanning electron microscope. In vitro bioactivity tests in Simulated Blood Fluid were performed for up to 28 days, especially for the membrane containing 50 wt. % HA. SEM was used to characterise the surface microstructure of biocomposite membranes before and after soaking in SBF. It was observed that the formation of clusters in membranes increases with increasing amount of HA. The clusters are formed due to agglomeration and crystal growth of HA particles during drying of the membranes. The in vitro bioactivity was found to increase with soaking time of biocomposite materials in simulated blood fluid.Graphical abstract
Effect of Precipitant Additives on the Sludge Settling and Compacting Performance for Heavy Metal Wastewater Treatment

The purpose of this study is to investigate the impact of precipitant additives, i.e., calcium hydroxide (Ca(OH)2), calcium carbonate (CaCO3) and recycled sludge (RS), on the settling and compacting performance of sludge formed in the process of heavy metal wastewater treatment using bio-polymer ferric sulfate (BPFS). The results show that CaCO3 is the most suitable additive since heavy metal removal, sludge settling performance, and compacting performance is improved by 20%, 83.3%, 23.5%, respectively. In addition, scanning electron microscopy and X-ray diffraction were measured for contrasting the sludge morphology and crystallinity. The results suggest that CaCO3 acted as seeding material produces the largest flocs. Moreover, the flocculation theory combined with zeta potential measurement was used to explain the sludge formation mechanism, which is proposed as charge neutralization by BPFS, sweep flocculation by amorphous precipitate, and bridging flocculation by polyacrylamide (PAM) in sequence. The improvement of sludge properties by adding CaCO3 benefits from the enhancement of sweep flocculation. In summary, the interaction mechanism between precipitant additives and sludge performance is well understood, thus providing useful information about adding precipitant additives to improve both the sludge settling properties and the quality of the treated water during the heavy metal wastewater treatment.
Effects of pH, Potassium Chloride, and Sodium Chloride on the Thermal and Rheological Properties of Gellan Gum Gels

The effects of pH on DSC curves and the breaking stress of gellan gum gels with and without Nacl or KCl were investigated. The breaking stress of all gels increased with decreasing pH down to pH 4. The difference between the breaking stress of nonheated gels and that of gels reheated for 2 h at 90 °C became larger with increasing pH. The exothermic enthalpy (ΔH) of all samples became minimum at pH 4. The DSC cooling and heating curves for all samples did not show any peak at pH 2. Repeated observations of DSC curves were carried out from 99.9 to 1.0 °C. Exothermic peaks of all gels at pH 4 and 6 shifted to lower temperatures, and the peaks of DSC heating curves of gels without salt at pH 8 shifted to higher temperatures with increasing numbers of heating and cooling cycles.
Modification of Coal Tar Pitch to Reduce the Carcinogenic Polycyclic Aromatic Hydrocarbons

This research investigated on reducing carcinogenic polycyclic aromatic hydrocarbons(PAHs),especially benzo[a]pyrene (BaP) in coal tar pitch by modifying with the two selected modifiers: Paraformaldehyde and Epoxy Resin. The reaction emphasis on the change of temperature, reaction time and the quantity of the modifiers. The results indicated that Paraformaldehyde and Epoxy Resin could decrease the PAHs content greatly. The BaP decreasing rate reached 75.86% and 53.45% respectively. And the BaP equivalency content of the pitch decreased from 2.94% to 1.41% and 1.47% respectively. The properties of the modified coal tar pitch, including soft point (SP), toluene insolubles (TI), quinoline insolubles (QI) have changed a lot.
Pyrones. X: Lateropyrone, a new antibiotic from the fungus Fusarium lateritium nees

Lateropyrone, 5-hydroxy-9-methoxy-2-methyl-4H,6H-pyrano[3,4-g]-1-benzopyran-4,6-dione-8-carboxylic acid, 1, has been isolated from cultures of the fungus Fusariumlateritium Nees, and shown to have inhibitory activity against the growth of a gram-positive bacterium and a yeast. A crystal structure of the dimethyl derivative of lateropyrone, 2, was determined. The crystals are monoclinic, space group P21/c, with a = 9.663(4), b = 22.317(9), c = 7.747(5) A, β = 113.03(4)°, Dc = 1.496 g cm−3, V = 1538(1) A3, T = 25 °C, C17H14O8. The structure was refined to R = 0.0543 by least squares using 2100 observed, independent reflections measured on a 4-circle diffractometer, to obtain 241 parameters. The linearly fused tricyclic ring system is only approximately planar. In- and out-of-plane distortions are rationalized in terms of molecular overcrowding.
Urea and Manure Effects on Soil Nitrogen and Corn Dry Matter Yields

Fresh (FC) and composted (CC) cow (Bos taurus) manures, liquid hog (Sus scrofa domesticus) manure (HM), and urea (U) were applied as N sources for silage corn (Zea mays L., hybrid W844) production on a Chicot (Hapludalfs) and a St. Benoit soil (Eutrochrepts) at rates of 0 to 240 N ha⁻¹. Soil NO₃-N levels were significantly increased while soil NH₄-N levels were only temporary increased by N additions. Highest NO₃-N levels were noted 30 and 60 d (June and July) after N applications for the St. Benoit and the Chicot soils respectively. Hog manure resulted in more NO₃-N compared with FC and CC manures. One to 5 kg manure-N was found to be equivalent to 1 kg of urea-N in terms of increasing soil NO₃-N levels at the end of growing season. Differences between surface spreading or incorporating of manures on corn dry matter yields (DMY) and N uptake were not significant. Nitrogen uptake increased with increases in N application rates and was higher with HM than with CC or FC manures. Regression between DMY or N uptake and N application rates showed linear relationships with manure-N and quadratic relationships with urea-N. In 1984, 1 to 4 kg manure-N resulted in similar corn DMY as 1 kg urea-N. Cumulative effects of treatments on yields and on nutrient uptake observed in second and third years were greater on the St. Benoit soil than on the Chicot soil.
Characterizing the Flaming Ignition of Cellulose Fuel Beds by Hot Steel Spheres

In this work, the flaming ignition of powdered cellulose fuel beds by hot steel spheres of various diameters and initial temperatures is studied. The spheres were heated in a tube furnace and then dropped onto a fuel bed, and the occurrence of flaming ignition or lack thereof was visually observed and recorded. A multivariable logistic regression method was developed and used to obtain an approximate ignition probability distribution and flaming ignition limits for the parameter space investigated. Each test was also recorded using high speed Schlieren videography, which gave qualitative insight into the ignition process. Ignition of larger spheres (>8.5 mm) appears to depend more strongly on sphere temperature than diameter. Alternatively, ignition by small spheres (<3.5 mm) appears less sensitive to temperature and more sensitive to sphere size. It was also confirmed that ignition cannot be predicted by bulk sphere energy alone. Flaming ignition occurs in the gas phase, in some cases away from the ball surface. Based on this and other evidence, it is proposed that ignition occurs when heat generation in the surrounding mixture of gasified fuel and air over-comes diffusive losses long enough for thermal runaway to occur. It is also noted that bulk energy may be important for predicting ignition by small spheres because of the increasing importance of the energy required to pyrolyze and produce an ignitable mixture.
Chromatographic Study of Adsorption of n-Alkanes on Zeolites at High Temperatures

Henry constants, adsorption enthalpies, and entropies of C5−C10 n-alkanes were determined using the chromatographic method on BEA*, TON, MOR, and FAU type zeolites in the temperature range 200−375 °C. On all zeolites, the Henry constants of the linear alkanes increase exponentially with the alkane chain length. Adsorption enthalpies and entropies are related to the pore geometry and have an opposite effect on the Henry adsorption constant: smaller pore sizes lead to a strong increase of the adsorption enthalpy with the carbon number, which is favorable for the adsorption equilibrium. However, this increase of −ΔH0 with CN is accompanied by a high loss of degrees of freedom in small pores, leading to a strong increase of the adsorption entropy with chain length and counterbalancing the positive effect of the enthalpy on the Henry constants. On large-pore zeolites, the opposite effect is observed. The strongest increase of the Henry constants with the carbon number occurs on zeolites in which an intermedia.
Organic Geochemistry of the Paleozoic Petroleum System of Saudi Arabia

The Paleozoic petroleum system of the Central and Northern Provinces of Saudi Arabia contains one of the most prolific oil-prone source rocks of Silurian age worldwide, the Qusaiba shale of the Qalibah Formation. This source rock is responsible for charging the large, gentle structures of the Central Province with billions of barrels of light, sweet, crude oil. Organic geochemical methods such as biomarkers, organic petrography, and characterization of the source rock facies have been used to determine the most likely candidate source rock for the Paleozoic oils of Saudi Arabia. By using detailed extract and oil characterizations, the basal «hot» shales of the Qusaiba Member of the Silurian Qalibah Formation have been correlated to the oils reservoired in the Permian sands of the Central Province of Saudi Arabia.
Remarks on polyelectrolyte conformation

We discuss the conformations of linear polyions assuming that a) the corresponding uncharged chain is flexible ; b) electrostatic forces dominate the monomer-monomer interactions; c) no salt is added. 1) For the dilute case (non overlapping chains) correcting a recent self-consistent calculation by Richmond [1a], we find an overall polyion size R = Nd which is a linear function of the polymerization index N in agreement with the early work of Hermans and Overbeek, [1b], Kuhn, Kunzle, and Katchalsky [1c]. 2) There is a range of very low concentration c (c** c**) : here we expect that the polyions build up a 3-dimensional periodic lattice ; however, the detection of such an extremely dilute lattice appears difficult. 3) Practically all experiments on salt-free polyelectrolytes have been performed at concentrations c > c* where different chains overlap each other. To discuss this regime we restrict our attention to cases where the charge per unit length is near (or above) the condensation threshold : then a single length ξ( c) characterizes the correlation; in 3 dimensions ξ scales like the Debye radius associated with the counter ions. We consider several possible conformations : a) hexagonal lattice of rigid rods ; b) cubic lattice of rigid rods ; c) isotropic phase of partially flexible chains. The various rigid rod structures appear to have very similar electrostatic energies. This suggests that the isotropic phase might possibly be the most favorable. We analyse this latter phase using the same scaling methods which have recently been helpful for neutral polymer solutions (2). In the isotropic model each chain behaves like a succession of segments of size. Inside one segment electrostatic effects are important and similar to case (1) above. Between segments the interactions are screened out, and tach chain is ideal on a large scale, with radius R (c) ∼ c-1/4 N1/2 . If we (tentatively) assume that the dynamical effects of entanglements are weak, we are than led to a viscosity ηsp/c ∼ Nc-1/2.
Relationship between change in ADL during two weeks from admission and ADL at discharge in post-stroke patients admitted to Kaifukuki rehabilitation wards

Hori H, Sonoda S, Watanabe M, Okuyama Y, Okamoto S, Okazaki H. Relationship between change in ADL during two weeks from admission and ADL at discharge in post-stroke patients admitted to Kaifukuki rehabilitation wards. Jpn J Compr Rehabil Sci 2019; 10: 82-87. Objective: In post-stroke patients admitted to Kaifukuki (comprehensive inpatient) rehabilitation wards, we investigated whether the level of activities of daily living (ADL) at discharge differs depending on the change in Functional Independence Measure (FIM) score from admission to 2 weeks post-admission. Methods: A total of 2,636 post-stroke patients were studied. Total scores of FIM motor subscale (FIMM) were divided into 7 grades (FIMM7) and total scores of FIM cognitive subscale (FIMC) were also divided into 7 grades (FIMC7). The FIMM7 or FIMC7 on admission and that at 2 weeks post-admission were compiled in a cross table, and the median values of FIMM on admission, FIMM at discharge, FIMM gain, and FIMM efficiency were calculated, and the differences were analyzed statistically. Results: For both FIMM7 and FIMC7, as the difference in score between admission and 2 weeks post-admission became greater, more combinations showed significantly higher FIMM at discharge and higher FIMM gain/efficiency. Conclusion: Patients showing improvement in FIMM or FIMC from admission to 2 weeks post-admission may have better ADL outcomes.