Miracle-dz/UniFAR-FTUs huggingface dataset:
Equilibrium structure and dynamics of organic crystals by Monte Carlo simulation: critical assessment of force fields and comparison with static packing analysis

The atom–atom intermolecular force field AA-CLP with subdivision of interaction energies into Coulomb-polarization, dispersion (London) and repulsion (Pauli) terms is applied to the Monte Carlo simulation of 63 organic crystals taken from the literature to cover the most common functionalities of organic and biological chemistry. Non-rigid molecules are treated as ensembles of rigid fragments connected by torsional degrees of freedom, for which ad hoc potentials are obtained from MP2-631G** calculations. The performance of the method and force field is assessed by comparison with experimental structures at 100 and 300 K. Molecular orientation, cell dimensions and sublimation energies are well reproduced, with some exceptions for fluorinated and nitro compounds. Simulated density and energy changes with temperature reproduce experimental observations. Calculated radial density functions and correlation functions reveal details of material behaviour at the atomic level, including librational amplitudes. Dynamic phenomena like methyl group rotations or rotational diffusion in the classic case of the benzene derivatives and adamantane are described in a satisfactory manner. Competition between intra- and intermolecular factors in biphenyl and other double-ring compounds is accurately described. Use of dynamic or Monte Carlo simulation gives a realistic picture of crystal structure and bonding, which often contrasts with simplistic views postulated on the basis of averaged atomic positions and static packing diagrams, as produced in typical single-crystal X-ray diffraction experiments.
The importance of soil solution chemistry to nickel toxicity on barley root elongation

Abstract The influence of soil solution properties on nickel (Ni) toxicity and its effects on barley root elongation were investigated using 17 Chinese soils amended with Ni chloride, which may or may not have undergone leaching treatment. The Ni in the soil solution was recorded in the soil pore water and in the extraction with 0.01 M CaCl2. The ranges of effective concentrations for CaCl2 -extracted Ni that caused 10% root elongation inhibition (EC10) and for 50% inhibition (EC50) varied widely from 65 to 114 times between different soils. The EC10 and EC50 values for Ni toxicity thresholds in soil pore water for unleached and leached soils varied from 40 to 124 times. In most soils, the toxicity thresholds for Ni, based on 0.01 M CaCl2 or soil pore water extractions, were not significantly affected by leaching. Regression models between toxicity thresholds and soil solution chemistry were developed and showed that Mg and S in soil pore water were the two most important factors affecting the extent of Ni toxicity on barley root elongation. However, pH showed only a weak correlation with toxicity thresholds.
Atom movements: Diffusion and mass transport in solids

The present book is the result of diverse courses on diffusion. It is intended to give as complete an overview as possible of diffusion in solid media, while relating the process of diffusion to both their physical bases and their applications. A series of a real situations is covered in this account, from self-diffusion of radiotracers to the more complex cases of mass flow under chemical or thermal gradients or under electric fields, or diffusion in structures of lower dimensionality (surfaces and interfaces). In all these analyses, no category of materials was favored; metals, ionic crystals, oxydes, and semiconductors all had their turn. Only polymers were not specifically touched. One chapter is specifically devoted to techniques for studying diffusion, including methods of numerical simulation, and a last and long chapter gives a number of metallurgical phenomena in which diffusion plays a fundamental role.Jean Philibert is professor of Materials Science at the University of Paris-Sud. Translation from french by Steven J. Rothman, Metallurgist, Argonne National Laboratory.
Connection between quasielastic Raman scattering and free volume in polymeric glasses and supercooled liquids

Quasielastic light scattering (QLS) in the frequency interval 100–1000 GHz is measured in some polymers: polycarbonate, polybutadiene, polystyrene, and poly(methyl methacrylate). To describe the spectra, a model of the fast picosecond relaxation processes responsible for the QLS, which is based on the damping of the boson peak vibrations by the dynamic hole volume fluctuations, is used. Within the frame of the model, the intensity of the fast relaxation process is proportional to the fractional dynamic hole volume (which above the glass transition temperature Tg is known as the fractional free volume). The hole volumes can be measured using the positron annihilation lifetime spectroscopy (PALS). The comparison of the literature PALS data in the four polymers with the QLS shows an apparent correlation between the relaxation strength and the fractional dynamic hole volume in good agreement with the predictions of the model.
Rapid radiation degradation in the XPS analysis of antibacterial coatings of brominated furanones

Brominated furanones are promising antibacterial compounds, both in solution and immobilized on solid surfaces, and there is interest in their utilization as protective coatings on biomedical devices to combat device‐centered infections. The rational design and optimization of antibacterial furanone coatings requires detailed spectroscopic surface characterization of the coatings produced and correlation of surface analysis data with antibacterial performance. However, as reported in this study, the extreme sensitivity of brominated furanones to radiation damage in the course of XPS analysis greatly complicates characterization. Our data show that rapid degradation occurs, as shown by the emergence of a signal assignable to Br− ion in the Br 3d spectrum. This Br− is water soluble as shown by washing experiments, whereas the CBr signal does not become reduced during washing, consistent with covalent interfacial immobilization of the furanone molecules. Furanone molecules were immobilized onto two different hydrogel interlayers (polyacrylic acid and polyethylene oxide (PEO)), and XPS analyses show that the interlayers did not suffer significant radiation degradation; the damage is limited to the furanone molecules. The results of this study may assist in XPS analyses of other brominated compounds on surfaces; the possibility of Br− ions deriving from XPS analysis–damage must be investigated before assigning their generation to side reactions in the coating or surface‐modification procedure. Copyright © 2006 John Wiley & Sons, Ltd.
Nanoporous Gold Leaf for Amperometric Determination of Nitrite

Ultra-thin free-standing nanoporous gold leaf made by dealloying exhibits excellent electrocatalytic activities toward nitrite oxidation. The electrochemical responses of nitrite ions on this novel nano-electrode is found not dependent on pH over a wide range from 4.5 to 8.0, which is markedly different from that of gold oxidation, a process known to be highly pH-sensitive. Amperometric study shows a linear relationship for nitrite determination in a concentration range from 1 µM to 1 mM. This nanostructured gold electrode displays good stability, repeatability and selectivity which suggests its potential for the development of new electrochemical sensors.
Brownian-dynamics simulations of model stabilised colloidal dispersions under shear

We have continued our investigation of the effect of shear flow on the microstructure of model near-hard-sphere dispersions by using the computer simulation technique of Brownian dynamics (BD) in the approximation ignoring many-body hydrodynamics. We have determined a non-equilibrium phase diagram that gives the shear rate at which there is a transition between an amorphous liquid-like structure at low shear rate to an ordered phase at high shear rates, as a function of the fraction of solids. We have derived the mathematical Fourier-transform procedure needed to compute the structure factor (and therefore predicted scattering intensities) from the model system under shear, subject to sliding periodic boundary conditions. The relationship between the real space ‘snap-shot’ configurations and these structure factors is thereby elucidated. We also make a quantitative comparison between the scattering intensities obtained by recent light-scattering experiments and those predicted by our model. There is some qualitative agreement between the experimental and simulation intensites for moderate shear thinning; however, the model forms an ordered ‘string’ phase at low volume fractions and infinite shear rates, which the experiments do not confirm.
Molecular structure of the NS free radical by gas-phase electron paramagnetic resonance

The analysis of the electron paramagnetic resonance spectrum of 14N32S (2Π3/2, J = 3/2) in the gas phase has led to the rotational constant the 14N nuclear hyperfine constant h = 56·99 ± 0·23 Mhz when b = 0, or 57·61 ± 0·23 Mhz when a theoretical value b = 63·66 Mhz was assumed, the 14N quadrupole coupling constant eQq = -2·86 ± 0·31 Mhz and the electronic g value, . The l-uncoupling constants evaluated from the Λ-doubling constant which was obtained by a pure microwave spectrum were used for the computation of gl + ½g e mentioned above.
Synergy Between N and O Atom Action and Substrate Surface Temperature in a Sterilization Process Using a Flowing N2‐O2 Microwave Post Discharge

It is demonstrated here that the sterilization process using a flowing N 2 -O 2 post discharge reactor involves a specific heating of the bacteria metal holder produced by heterogeneous O and N atoms recombination. Such heating increases with N and O-atom concentrations, which can be varied with the microwave discharge power. It also depends on the metallic material of the holder: a brass support can reach a maximum surface temperature of 120 °C while the surface temperature of the stainless steel holder increases to 60-70 °C after 40 min of exposure to a N 2 -5% O 2 post discharge at 0.6 kPa (5 Torr), 1 L n . min - 1 and 100 W. It is demonstrated that the E. coli destruction efficiency increases with N and O atom density at a constant temperature (60 °C) of the stainless steel support and with the support temperature (up to 60°C) at constant N and O atom densities. A cumulative effect was also found with increasing N and O atom density and of the support temperature.
PM 1 , Intermodal (PM 2.5-1 ) Mass, and the Soil Component of PM 2.5 in Phoenix, AZ, 1995-1996

Concentrations of size-resolved airborne particulate matter measured in Phoenix, Arizona in 1995-1996 indicate a strong linear relationship between the soil components of PM 2.5 and the intermodal PM concentration and similarly between the nonsoil components of PM 2.5 and the PM 1 concentration. Moreover, the ratio of PM 1 to intermodal PM varies considerably at all reported concentrations of PM 2.5 , and this variation appears to be systematically related to the proportion of PM 2.5 comprised of soil components.
Tunneling transport in polyoxometalate based composite materials

Molecular materials containing tungsten polyoxometalates as the active elements embedded into polymer matrices are investigated as candidates for electronic device applications. The transport properties of these materials are investigated varying the interelectrode spacing and the polyoxometalate concentration. The I–V characteristics of planar devices reveal a conductivity peak at room temperature conditions for intermolecular distances less than 3 nm and electrode distances less than 100 nm. The transport characteristics are discussed in terms of tunneling mechanisms.
Long‐term performance degradation of various kinds of photovoltaic modules under moderate climatic conditions

Various kinds of photovoltaic (PV) modules have been developed and practically operated as PV systems up to present. Investigation of the long‐term reliability of PV modules is indispensable for the use of PV systems as reliable energy sources. In this study, we show the results of outdoor exposure test in which the performance of 14 PV modules composed of five different kinds made by six different PV manufacturers have been measured since July 2004. The average performance is calculated in each year from 2005 to 2008, and the performance degradation is quantitatively evaluated. The results are that the magnitude of the performance degradation can be clearly classified by the kinds of the PV modules. The performance difference of the single‐crystalline silicon (sc‐Si) modules between 2005 and 2008 is from 1.9% to 2.8%. Polycrystalline silicon (pc‐Si) modules show performance degradation from 0.7% to 1.4%. The performance of an amorphous silicon/crystalline silicon (a‐Si:H/c‐Si) decreased by 0.7%. Although a pair of a‐Si modules had been already exposed to sunlight for about 6 months, the pair of modules show 4.4% of performance degradation. More than half of the performance degradation happened during the initial period from 2005 to 2006. This indicates that it takes about 2 years until the performance of a‐Si modules is stable. The performance is quite stable after 2006. Interestingly, the performance of the cupper indium gallium diselenide modules in 2008 is about 0.8% higher than that in 2005. Copyright © 2010 John Wiley & Sons, Ltd.
Phosphorus and cadmium sorption by red soils and fe oxide concentrates from Thailand.

The objectives of this study were to investigate phosphorus (P) and cadmium (Cd) sorption behavior of red soils and of their Fe oxide concentrates. The B horizon of four red soils and their Fe oxide concentrates (prepared by 5M NaOH treatment) from Thailand including Chok Chai (Ci), Ao Luek (Ak) and Yasothon(Yt) soil series and Khao Kho (Kk) soil were used. Phosphorus sorption of red soils in this study was pH independent at ~3.0-7.0 pH range and was in the order of Kk > Ak > Ci > Yt . In contrast, P sorption by Fe oxide concentrates was pH dependent at 3.010. 0 pH range and was in the order of Ci > Kk > Ak > Yt. Phosphorus sorption by whole soils had positive relationship with soil properties including CEC, Ald, Feo, SSA, OC, Alp, Fep, Goe/(Goe+Hem), Alo and %clay, but the P sorption of the Fe oxide concentrates was related only to the IEP. Synthetic goethite had a higher P sorption capacity than did the Fe oxide concentrates except for Ci, specifically at low pH. Cadmium sorption of red soils and their Fe oxide concentrates were highly pH dependent at ~5.0-8.0 pH range and Cd sorption increased with increasing pH. The difference in Cd sorption values among samples were observed at pH ~7.0 for both whole soils and Fe oxide concentrates. Cadmium sorption of these red soils and their Fe oxide concentrates indicated soil pH as the important factor to control the activity of Cd, but it has less effect on their available P.
Multi-component continuous separation chip composed of micropillar arrays in a split-level spiral channel

The separation and concentration of blood components or biological functional microparticles, have become indispensable in various biomedical and environmental applications. In this paper, a chip with two rows of micropillar arrays along a spiral-channel, in which plasma and various blood cells with different sizes can be separated or enriched simultaneously, has been achieved. The proposed method combines crossflow, centrifugation and size-selective separation approaches. Specially, a 40 μm-high step, which can increase the pressure difference, is designed between the inner and middle channel to enhance the separation efficiency and purity. In the chip with split-level channels, the number of red blood cells (RBCs) gathered from the inner outlet decreased significantly, and the collected plasma volume increased, compared to those in the plain one.
The structure of native cellulose

Native cellulose has been shown to consist of a crystalline array of parallel chains, based on the X‐ray diffraction data for specimens from the sea alga Valonia ventricosa. The unit cell is monoclinic with dimensions a = 16.34 Å, b = 15.72 Å, c = 10.38 Å (fiber axis), and β = 97.0°. The space group is P21 and the cell contains disaccharide segments of eight chains. Models containing chains with the same sense (parallel) or alternating sense (antiparallel) were refined against the intensity data using rigidbody least squares procedures. The results show a preference for a parallel chain structure with specific chain polarity with respect to the c axis. The refinement places the CH2OH side chains approximately 20′ from the so‐called tg conformation, with a result that an 02′H…06 intramolecular bond is formed. The structure also contains an 03H…05′ intramolecular bond and an 06H…03 intermolecular bond along the a axis. All these bonds lie in the 020 planes, and the structure is an array of hydrogen‐bonded sheets. A major consequence of this work is that regular chain folding can be ruled out and cellulose is seen as extended chain polymer single crystals.
Work Function Tuning of Ti x Si y N z Electrodes Using Partial Saturation of Chemisorbing Surface during Pulsing Chemical Vapor Deposition

In this article, the achievement of TixSiyNz metal gates with tunable work function is demonstrated using partial saturation during pulsing chemical vapor deposition. Thin films were deposited on SiO2 using a pulse sequence with tetrakisdimethyl amido titanium, NH3, and SiH4 precursors. By adjusting the silane pulse, the chemisorption kinetics of silane on the surface is finely tuned to control the composition of TixSiyNz layers. Their effective work functions were measured in metal-oxide-semiconductor capacitors. Results indicate that the effective work function can be accurately monitored in the range of 4.35-4.60 eV by adjusting the silane pulse time.
Application of perturbation theory to the crystal–melt interface

The Abraham–Singh perturbation theory is applied to the case of the interface between an fcc crystal and its melt. The starting point is the density distribution of a hard‐sphere liquid near a hard wall. The perturbation theory corrects the hard‐sphere fluid density distribution by accounting for the soft repulsive nature of the crystal face with respect to the fluid atoms, this interaction being approximated by its two‐dimensional Boltzmann average potential. Account is taken of the thermal motion of the crystalline molecules at the interface. The theoretical density distribution is in good agreement with that obtained from a molecular dynamics experiment, for both (100) and (111) faces.
Long- and short-term temperature differences affect organic and inorganic nitrogen availability in forest soils

Boczulak, S. A. , Hawkins, B. J., Maynard, D. G. and Roy, R. 2015. Long- and short-term temperature differences affect organic and inorganic nitrogen availability in forest soils. Can. J. Soil Sci. 95: 77-86. Soil microbial activity determines rates of decomposition and is strongly influenced by temperature. Soil microbial communities may be adapted to site characteristics, including temperature, through physiological modification of microbial populations or changes in species composition; however, response to short-term changes in temperature may also occur. We searched for evidence of short- and long-term temperature response of microbial communities involved in soil nitrogen (N) cycling by measuring the relative availability of organic and inorganic N forms in forest soils from a high and a low elevation site, incubated at 10, 16 and 20°C for 16 wk. By week 16, ammonium concentrations were greater in soils incubated at 16 and 20°C than at 10°C, and in soil from the low elevation site, compared with high elevation. Nitrate concentrations increased in soil from the low elevation site incubated at 16 and 20°C, but changed little in other treatments. Assessment of autotrophic nitrification potential showed gross nitrification in soil from the low elevation site was likely from classical chemolithotrophic nitrifiers. Organic N concentration increased over time in the 16 and 20°C incubations of soil from the low elevation site, but only increased in the 20°C treatment for soil from the high elevation site. Long-lasting site effects were indicated by the more active microbial community in soil from low elevation, which could be related to site temperature. Evidence of short-term temperature response of N cycling processes was observed in soils from both elevations.
Monitoring of indoor particulate matter during burning of mosquito coil, incense sticks and dhoop

Background: Indoor combustion source, like incenses, are commonly used for aesthetic and religious purposes in various indoor as well as outdoor environments. The combustion leads to the production of a large amount of smoke, which can pose a health risk due to inhalation exposure of particulate matter (PM). Objective: Monitoring of PM (PM 10 , PM 2.5 , and PM 1 ) during the preburning, burning and postburning phases of incenses (agarbatti and dhoop) and mosquito coil in the indoor environment. Materials and Methods: The monitoring of PM was carried out using the Grimm Portable Laser Aerosol Spectrometer and dust monitor model 1.108/1.109. The substances used were mosquito coil, incense (sandal), incense (floral sticks) and dhoop. The data were analyzed using the SPSS statistical package version 14.0 for windows (SPSS, Chicago, IL, USA), using one-way analysis of variance to compare the PM 10 , PM 2.5 and PM 1.0 concentration levels. Results: The mean concentrations of PM 10 (1879.7 μ/m 3 ), PM 2.5 (1775.4 μ/m 3 ) and PM 1 (1300.1 μ/m 3 ) during burning phase were highest for dhoop. The mean concentrations of PM 10 , PM 2.5 and PM 1 during burning of mosquito coil were 259.2 μ/m 3 , 232.4 μ/m 3 and 214.0 μ/m 3 respectively. The burning of incense (flora) had PM 10 (854.1 μ/m 3 ), PM 2.5 (779.8 μ/m 3 ) and PM 1 (699.8 μ/m 3 ), which were higher, in comparison to burning of incense (sandal). The particulate emission during the burning of dhoop (PM 10, PM 2.5, PM 1 ) was significantly higher (P < 0.05) than incense (sandal and flora) and mosquito coil. The concentrations of PM 10 , PM 2.5 and PM 1 even during postburning phase were significantly higher for dhoop in comparison to other three products, resulting in prolonged exposure even after the cessation of burning phase. Conclusion: The study suggests burning of dhoop, incense sticks and mosquito coil in the indoor environment emit quiet higher respirable PM, which may accumulate on prolonged exposure and lead to respiratory illnesses.
Room-temperature mixed-solvent-vapor annealing for high performance perovskite solar cells

In this paper, we introduce a room-temperature mixed-solvent-vapor annealing (rtMSVA) method to fabricate high performance perovskite solar cells (pero-SCs) based on MAPbI3−xClx without the need for thermal annealing (TA). An ultra-smooth perovskite thin-film with high crystallinity was obtained by the DMF/CB mixed-solvent (1 : 20, v/v) vapor annealing at room-temperature without TA and the power conversion efficiency (PCE) of the pero-SCs reached 16.4%. More importantly, the reproducibility of the PCEs is quite good among 40 different devices. Furthermore, large active area pero-SCs were fabricated with the rtMSVA method. The PCEs of the pero-SCs based on ITO and flexible PET/Ag mesh electrodes with an active area of 1.21 cm2 reached 11.01% and 7.5%, respectively. We anticipate that rtMSVA would very possibly become a promising crystallization method for the fabrication of large area pero-SCs in the near future.