Miracle-dz/UniFAR-FTUs huggingface dataset:
Alkylation of Si Surfaces Using a Two-Step Halogenation/Grignard Route

Despite the fact that H-terminated, HF-etched Si crystals are the starting point for construction of most contemporary electronic devices,1 little is known about the chemical reactions of H-terminated Si surfaces under ambient temperature and pressure.2,3 Functionalization of Si without partial oxidation and/or formation of electrical defects is potentially important in fabricating improved electronic devices4,5 as well as in measurement of charge transfer rate constants at semiconductor/ liquid contacts.6 One recently described approach involves the reaction of HF-etched Si(111) with olefins and organic diacyl peroxides, in which formation of a self-assembled (near)monolayer of Si-alkyls was hypothesized.2 We report here an alternative strategy to functionalize HF-etched Si surfaces involving halogenation and subsequent reaction with alkyl Grignard or alkyl lithium reagents. We report vibrational spectroscopic and temperature programmed desorption data which confirm that the alkyl groups are bonded covalently to the Si surface, and we demonstrate that such overlayer formation can impede the undesirable oxidation of Si in a variety of environments while providing surfaces of high electrical quality. The H-terminated Si surface7 was first exposed to PCl5 for 20-60 min at 80-100 °C, in chlorobenzene with benzoyl peroxide as the radical initiator.8,9 Upon chlorination, the XP survey spectra (Figure 1) showed peaks at 270.2 ( 0.4 binding electron volts, BeV, (Cl 2s) and 199.3 ( 0.4 BeV (Cl 2p), indicating that this procedure yielded Cl on the surface. The high-resolution XP spectrum of the Si 2p peak of this surface displayed, in addition to the substrate Si signal, an additional peak located at 0.98 ( 0.12 BeV higher in binding energy (Figure 2) whose position and intensity was consistent with the formation of a surface Si-Cl bond.10 Auger electron spectra
Activation of giant silicalite-1 monocrystals combining rapid thermal processing and ozone calcination

A rapid thermal processing (RTP) technique combined with ozone/oxygen calcination was applied to activate and heal the structure of a 1.1 mm2 section of a silicalite-1 giant monocrystal. Crystallinity was monitored by single crystal X-ray diffraction and high sensitive thermogravimetry (TGA) was performed to prove the complete removal of the structure directing agent.
Plasmonic Field Effect on the Hexacyanoferrate (III)-Thiosulfate Electron Transfer Catalytic Reaction on Gold Nanoparticles: Electromagnetic or Thermal?

The rate of the catalytic reaction between hexacyanoferrate (III) and thiosulfate on gold nanoparticles is found to increase when irradiated with light in resonance with surface plasmon absorption of the gold nanoparticles. Turning on the plasmonic field by turning on light at the surface plasmon extinction band wavelength could increase the rate by one of two possible mechanisms. In the first one, the electromagnetic field could change its radiative or nonradiative electron transfer process (Mechanism I). In the other mechanism (Mechanism II), the strongly absorbed light by the gold nanoparticles is rapidly converted from light energy into heat energy that increases the temperature of the medium and increases the reaction rate. In order to determine which mechanism the plasmonic catalytic effect follows, we determined the activation energy of the reaction by heating the reaction solution via two different methods: irradiation at the surface plasmon resonance of the gold catalyst and by direct heating in .
Equations for Predicting Soil Organic Carbon Using Loss‐on‐Ignition for North Central U.S. Soils

Samples of 255 noncalcareous A, Ap, and AB horizons from selected major land resource areas (MLRA) in the north central USA were used to develop equations for predicting organic C content, as determined with a Leco C analyzer, from weight loss-on-ignition (LOI). Organic C concentrations of the samples ranged from 1.09 to 114.6 g kg -1 . Within each MLRA, strong linear relationships were observed between LOI and organic C measured by the Leco instrument, with r 2 ranging from 0.94 to 0.98. Predictive equations developed by least-squares regression were significantly different for individual MLRA's. Loss-on-ignition is a rapid, inexpensive, and accurate method for estimating organic C concentration in soils of the north central USA. We recommend that unique predictive equations be developed for individual soil-geographic regions.
Identification and Quantitation of Acetone Extractives of Wood and Bark by Ion Exchange and Capillary GC with a Spreadsheet Program

On decrit une procedure pour l'identification et la mesure des composants des matieres extraites par l'acetone d'echantillond de bois et d'ecorce. La procedure comprend : 1) extraction par l'acetone; 2) chromatographie d'echange d'ions permettant le fractionnement des extraits en acides faibles, acides forts et composes neutres; 3) chromatographie gazeuse sur colonne courte permettant le fractionnement des composants; 4) programme sous tableur permettant l'identification et la determination quantitative des composants de l'extrait.
Lignin Peroxidase Production by Phanerochaete chrysosporium Immobilized on Polyurethane Foam

Production of lignin peroxidase by a white-rot basidiomycete, Phanerochaete chrysosporium, was investigated experimentally using polyurethane foam as a carrier of immobilized fungal mycelia. The immobilized cell culture using polyurethane foam as a carrier of mycelia yielded significantly greater lignin peroxidase activity than the conventional stationary liquid culture. The effects of operational conditions, such as the kind and number of polyurethane foam cubes, glucose concentration and temperature, on the lignin peroxidase production were examined. Addition of 0.05% Tween 80, 1 mM veratryl alcohol and 1 mM FeSO4-·7H2O greatly improved the production of lignin peroxidase up to 2,700 units/ml culture medium. The lignin peroxidase activity in this culture was about three times larger than that obtained from the culture cultivated in the absence of these additives. Step change incubation lowering the temperature from 37°C to 30°C over an incubation time of three days was carried out for the large scale production of lignin peroxidase, and this incubation gave the highest lignin peroxidase activity 3,800 units/ml culture medium.
Microstructure and Composition of TiO2 Nanotube Arrays Fabricated with HF and NH4F Electrolytes and Their Evolution during Annealing

The evolution of microstructure and composition of titanium dioxide (Ti0 2 ) nanotube arrays fabricated with hydrofluoric acid (HF) and NH 4 F electrolytes as a function of annealing temperature up to 400°C was investigated and compared using X-ray diffraction, scanning electron microscopy, and X-ray absorption near-edge structure spectroscopy. Results showed that TiO 2 nanotube arrays grown in HF electrolyte contained 90% amorphous Ti0 2 and 10% lower oxidation states of titanium from Ti 2+ (TiO) and Ti 3+ (Ti 2 O 3 ) cations. After annealing at 400°C, TiO 2 nanotube arrays underwent charge transfer and phase transformation to 93% anatase phase, 6% amorphous Ti0 2 , and 1% suboxides. In contrast, as-grown Ti0 2 nanotube arrays using NH 4 F electrolyte possessed less amorphous TiO 2 (82%) but more suboxides (18%) due to lower oxygen ion formation from scanty 3 wt % of H 2 0 addition. Its onset temperature of phase transformation was found to be higher than Ti0 2 nanotube arrays prepared by HF solution. Moreover, when annealed to 400°C, the crystallinity of TiO 2 nanotube arrays increased only by 86% for the anatase phase. The lower anatase phase could be attributed to the formation of (NH 4 ) 2 TiF 6 type compounds presumably formed by the reaction of TiF 2― 6 and NH + 4 ions dissociated from NH 4 F.
Neutron Depth Profiling Applications to Lithium-Ion Cell Research

This research proved that neutron depth profiling (NDP) is a useful technique that provides insight into lithium transport within lithium-ion cells. Studies were conducted utilizing NDP to examine lithium-ion cell behavior under three environmental and operational parameters: (i) storage of cells at temperature, (ii) cell charge/discharge cycling, and (iii) charge/discharge rate and state of charge. During the first study, where cells were stored at 50°C for up to 140 days, the solid electrolyte interface growth rate was determined to range up to 4.8 nm per day depending on the cell capacity. The second study involving cell charge/ discharge cycling did not reveal a statistically significant buildup of lithium near the cathode―electrolyte surface; however, the depth profiles showed an increased fluctuation in lithium concentrations as the number of cycles increased. Depth profiles from the third area of investigation quantified the linear relationship between lithium buildup near the cathode―electrolyte surface and the rate of charge (ranging from 0.1 to 4 C in this study).
Tertiary Alcohols from Hydrocarbons by Ozonation on Silica Gel: 1‐Adamantanol

Tertiary alcohols from hydrocarbons by ozonation on silica gel: 1-adamantanol product: adamantanol product: 1,3-adamantanediol Keywords: oxidation, CH2 CHOH and CHOR; replacement reactions, miscellaneous; silica gel; ozone; ozonizer and accessories; ozonizer and accessories, vessel
Ferricoxychloride and Hematite Nanoparticles: Synthesis and Phase Transformation

A synthetic procedure based on thermal hydrolysis of iron(III) chloride solutions for the preparation of hematite (α-Fe2O3) and ferricoxychloride (FeOCl) colloids consisting of nanoparticles (NPs) is described. Transmission electron microscopy indicated that both colloids consisted of particles smaller than 10 nm. X-ray diffraction measurements revealed transformation of FeOCl NPs into α-Fe2O3 NPs after a few months. The phase transformation was explained in terms of redissolution – recrystallization process. UV-vis spectroscopy was used for precise determination of the band gap of α-Fe2O3.
Stationary points on the potential energy surfaces of (C2H2)2, (C2H2)3, and (C2H4)2

Minima on the potential energy surfaces of (C2H2)2, (C2H2)3, and (C2H4)2 have been located by ab initio methods, using the Mo/ller–Plesset second‐order (MP2) procedure, with a DZP basis set. For (C2H2)2, a T‐shaped structure is predicted and for (C2H2)3, a C3h structure. For (C2H4)2 there are two candidates, a T‐shaped structure and a staggered‐parallel structure, and it is difficult to distinguish between them. Other stationary points have been located on the surfaces, but they are all found to be transition states, by the method of analytic second derivatives. Existing experimental data is insufficient to decide unequivocally as to the geometry of the minima. These calculations appear to resolve these questions and there is no contradiction with the data.
Safety of nuclear power

After 50 years since the foundation of the Nuclear Research Institute, Poland once more stands before the perspective of nuclear power plant (NPP) construction, this time with reactors of the 3rd generation, provided with effective safety systems. But during the past half century many questions have been asked, and they must be answered if the society is to agree to nuclear power development. The basic question is: Are small radiation doses, typical for operation of NPPs and nuclear fuel cycle installations, dangerous for human beings? Until the middle of XX century it had been believed that radiation doses below a certain threshold do not involve health hazards, but on the contrary – enhance human health. However, in 1959 the International Commission on Radiation Protection (ICRP) adopted the hypothesis that any dose of radiation, however small, can result in cell damages and eventually lead to cancer. This approach helped to stop nuclear weapon testing, and was reflected in the principle that radiation doses should be reduced to the values as low as reasonably achievable (ALARA). An example of the effects of this Safety of nuclear power Andrzej Strupczewski
Photocatalytic degradation of triethylamine on titanium oxide thin films

Photooxidation of triethylamine (TEA) in the presence of O2, N2, and H2O over titanium oxide (TiO2) was investigated using a flat plate reactor. TEA was photocatalytically oxidized to CO2 and some by-products on TiO2 thin film catalysts. The intrinsic oxidation rate of the reaction was determined and was dependent on TEA concentration, humidity level, and light intensity. Photocatalytic deactivation was observed in these reactions. Fourier transform infrared (FTIR) and temperature-programmed desorption with a mass spectrometer as a detector (TPD-MS) were used to characterize the surface of the catalyst and study the deactivation mechanism. FTIR and TPD-MS results suggest that accumulation of carboxylic acid species, –N–N=O, and some other carbonaceous species occurred during the reaction. These by-product species or intermediates were chemisorbed on the catalyst surface. They were stable under reaction conditions and might be responsible for deactivation of TiO2 by either poisoning the active sites directly or blocking the adsorption of TEA on the catalyst surface.
Increasing the intensity of protonated secondary ions in time-of-flight secondary ion mass spectrometry using a proton-conducting ionic liquid, diethylmethylammonium trifluoromethanesulfonate

To increase the secondary ion intensities of organic molecules, room-temperature ionic liquids were investigated in two time-of-flight secondary ion mass spectrometry (TOF-SIMS) experiments. First, ionic liquids as well as glycerol were tested as liquid matrices of arginine. The secondary ion intensity of protonated arginine was increased 200-fold by using a proton-conducting ionic liquid, diethylmethylammonium trifluoromethanesulfonate ([dema][TfO]). The matrix effect of [dema][TfO] was higher than that of glycerol, which is a typical matrix in SIMS. Next, ionic liquids were tested as primary ion beams. The number of protonated secondary ions of arginine was significantly increased by using a primary ion beam of [dema][TfO].
Arsenic speciation: limitations with direct hydride analysis

Speciation of inorganic arsenic(III) by hydride evolution directly into an atomic-absorption system was found to be subject to error when organic forms of arsenic (such as dimethylarsinic acid) were present. Organic forms of arsenic can produce an underestimation of total arsenic when the hydride response from concentrated acid is quantitated against inorganic arsenic. Hydride responses from solutions of various acidities are reported for dimethylarsinic acid, monomethylarsonic acid, inorganic arsenic(III) and inorganic arsenic(V). Even simultaneous equations did not provide a means of resolving mixtures of the four arsenic species investigated by using direct analysis of the evolved hydrides.
Control of Methyl Tertiary-Butyl Ether via Carbon-Doped Photocatalysts under Visible-Light Irradiation

The light absorbance of photocatalysts and reaction kinetics of environmental pollutants at the liquid-solid and gas-solid interfaces differ from each other. Nevertheless, many previous photocatalytic studies have applied the science to aqueopus applications without due consideration of the environment. As such, this work reports the surface and morphological characteristics and photocatalytic activities of carbon-embedded (C-TiO2) photocatalysts for control of gas-phase methyl tertiary-butyl ether (MTBE) under a range of different operational conditions. The C-TiO2 photocatalysts were prepared by oxidizing titanium carbide powders at 350 o C. The charac- teristics of the C-TiO2 photocatalysts, along with pure TiC and the reference pure TiO2, were then determined by X-ray diffraction, scan- ning emission microscope, diffuse reflectance ultraviolet-visible-near infrared (UV-VIS-NIR), and Fourier transform infrared spectros- copy. The C-TiO2 powders showed a clear shift in the absorbance spectrum towards the visible region, which indicated that the C-TiO2 photocatalyst could be activated effectively by visible-light irradiation. The MTBE decomposition efficiency depended on operational parameters, including the air flow rate (AFR), input concentration (IC), and relative humidity (RH). As the AFRs decreased from 1.5 to 0.1 L/min, the average efficiencies for MTBE increased from 11% to 77%. The average decomposition efficiencies for the ICs of 0.1, 0.5, 1.0, and 2.0 ppm were 77%, 77%, 54%, and 38%, respectively. In addition, the decomposition efficiencies for RHs of 20% , 45%, 70%, and 95% were 92%, 76%, 50%, and 32%, respectively. These findings indicate that the prepared photocatalysts could be effectively applied to control airborne MTBE if their operational conditions were optimized.
The Relative Importance of Abiotic and Biotic Transformation of Carbon Tetrachloride in Anaerobic Soils and Sediments

The relative contributions of abiotic and microbial processes and the role of dissolved species in the reductive dechlorination of carbon tetrachloride (CT) by natural soils and sediments were investigated. Microcosms were constructed using soils or sediments and site water from three locations, and then amended with electron acceptors and/or donors to stimulate the growth of iron- and sulfate-reducing bacteria and to promote the formation of minerals that can react with CT. Before spiking with CT, half the replicate microcosms were sterilized in order to measure the rates of abiotic CT transformation without any direct contribution from microbial dechlorination. Abiotic reaction rates were significantly greater than microbial rates for a range of initial CT concentrations, and for both iron- and sulfate-reducing conditions. In most cases, abiotic reaction rates were indistinguishable from total reaction rates (abiotic plus microbial), indicating a negligible microbial contribution to CT transformation. While in most microcosms the soil/sediment acted as the abiotic reductant, under certain conditions the supernatant was more reactive with CT than was the solid phase. For these conditions, we propose that the reactive species in the supernatant consisted of aqueous natural organic matter that underwent reduction or other transformation by S(-II) generated by sulfate-reducing bacteria.
AlGaN-Free Laser Diodes by Plasma-Assisted Molecular Beam Epitaxy

Room-temperature continuous wave lasing at 432 nm with a threshold current of 7.6 kA/cm2 for nitride-based laser diodes (LDs) grown by plasma-assisted molecular beam epitaxy is reported. The diodes were grown on c-plane GaN substrates with a threading dislocation density of 5×107 cm-2. We used a simplified laser structure design with GaN claddings where the optical modes were confined by the thick 120 nm In0.08Ga0. 92N waveguide. Our LDs show a high optical output power of 130 mW, a differential gain of 0.5 W/A, and a lifetime of 50 h.
CRITICAL DEFICIENCY LEVEL OF ZINC FOR CORN ON CALCAREOUS SALT-AFFECTED SOILS IN CENTRAL IRAN

A greenhouse experiment with 11 soil series and two zinc (Zn) rates (0 and 15 mg Zn kg−1 as zinc sulfate) was performed to determine critical deficiency level of Zn for corn (Zea mays L.) on calcareous salt-affected soils in central Iran. In addition, the most important soil properties affecting Zn phytoavailability were determined. Critical Zn deficiency levels were determined using the Cate-Nelson and Mitscherlich procedures. In most soils, application of Zn increased the dry matter yield, and Zn concentration and content in the shoot and root of corn. A positive correlation was observed between the soil electrical conductivity (EC) with Zn concentration in shoots, roots and whole plant while shoot Zn content was negatively correlated with buffer capacity of Zn in soil. Critical deficiency levels of Zn in soil for corn based on the Cate-Nelson and Mitscherlich method were 1.35 and 1.23 mg kg−1 for diethylenetriaminepentaacetic acid (DTPA)-extracted soil Zn, respectively.
High Sensitivity of CdS Nanoparticles and Their Self‐Assembled Films to Mn2+ Ions

The effects of Mn2+ ions (aq.) on the luminescence of CdS nanoparticles and their self‐assembled films were investigated. The luminescence peak of CdS nanoparticles at 645 nm does not shift, while the luminescence intensity of CdS nanoparticles and their self‐assembled films changes significantly with Mn2+ ion concentration. The lowest concentration of Mn2+ ions that can make the intensity change is 1.0 × 10−14 M. The results indicate that CdS nanoparticles and their self‐assembled films are very sensitive to Mn2+ ions (aq.).
NITROGEN TRANSFORMATIONS IN AN INCUBATED SOIL AS AFFECTED BY COMBINATIONS OF MOISTURE CONTENT AND TEMPERATURE AND ADSORPTION-FIXATION OF AMMONIUM

An incubation experiment was conducted on a clay loam soil using a factorial design to study the effects of temperature, water content, and applied NH4+-N on the change of NO3−-N and NH4+-N concentrations over time. Each of the factors and their interactions were highly significant, indicating the importance of the often neglected moisture–temperature interaction. Due to this interaction, optimum moisture contents for the activity of the nitrifying population appeared to be dependent upon temperature. Approximately one half of the added NH4+ was fixed within 2 days after (NH4)2SO4 was added to the soil. A concurrent study showed that soluble NH4+, exchangeable NH4+ and clay-fixed NH4+ existed in equilibrium upon adding NH4+. A Langmuir kinetic model might describe the relationship between exchangeable and fixed NH4+ whereas a nonlinear Freundlich equilibrium model yielded the best agreement between the soluble and exchangeable NH4+.
Some Reactions of 3-Methyl-5-oxo-1-phenyl-Δ 2 -pyrazoline-4-thiocarbohydrazide

The reactions of 3-methyl-1-phenyl-5-oxo-Δ 2 -pyrazoline-4-thiocarbohydrazide towards phenyl isothiocyanate, sodium nitrite, cyclohexanone, aromatic aldehydes, and carbon disulphide has been studied. The VilsmeierHaack reaction has been applied on 4-substituted pyrazolone derivatives.
Balancing the etching and passivation in time-multiplexed deep dry etching of silicon

For the Bosch deep silicon dry etch process with SF6–C4F8 a quantitative approach is developed. Essential plasma surface interactions and the transport properties of ions and radicals in high aspect ratio structures are unravelled. Balancing the interactions during etching and passivation pulses is essential for maximal profile control. In the anisotropic regime the etch rate is aspect ratio dependent largely due to depletion of fluorine radicals and with some involvement of passivation polymer redeposition. The anisotropic process tends to stop at a limiting aspect ratio because of improper removal of polymer passivation at the trench bottom. Both higher ion flux and ion energy are found to be crucial to push the Bosch process to higher achievable aspect ratios. Practical process implications are discussed. In situ ellipsometry shows that the polymer passivation step is a complex process with an ion induced component. More efficient removal of the passivation layer at the trench bottom by adjusting the p.